Investigation of Single and Two Bolt Connections ...

Investigation of Single and Two Bolt Connections Perpendicular to

Grain in Laminated Veneer Lumber

By

Monil Chintan Patel

Thesis submitted to the faculty of the

Virginia Polytechnic Institute and State University

in partial fulfillment of the requirements for the degree of

MASTER OF SCIENCE

in

CIVIL ENGINEERING

Dr. Daniel P. Hindman, Co-Chair

Dr. Finely A. Charney, Co-Chair

Dr. Joseph R. Loferski

August 7, 2009

Blacksburg, Virginia

Keywords: Wood Connections, Capacity, Laminated Veneer Lumber, Monotonic Loading,

Perpendicular to Grain, Bolts

Investigation of Single and Two Bolt Connections Perpendicular to

Grain in LVL

By

Monil Chintan Patel

ABSTRACT

Bolted connection with perpendicular to grain loading has been considered as a high

priority research area by Smith and Foliente (2002), for the advancement of the load resistance

factor design (LRFD) of connections. The results obtained from the experimental testing of this

research will provide information regarding the behavior of connections at conditions of capacity

and yield, and a comparison between single and two bolted connections for laminated veneer

lumber (LVL) from different manufacturers. Comparison of the experimental results with the

predicted results from three models: Technical Report -12 (AF&PA 1999), Van der Put and

Leijten (2000) and Jensen et. al. (2003), for single and two bolt connections loaded perpendicular

to grain will help in accurately predicting LVL connection behavior. Success in achieving the

goals of this research will provide enhancement of knowledge and information for single and two

bolted connections loaded in perpendicular to the grain connections for LVL and thereby help in

calibrating LRFD parameters on pure reliability basis in future. The variables considered

included LVL from two different manufacturers, single and two bolt connections with different

bolt sizes and loaded edge distances. The connections were loaded to capacity for all the tests.

Tests for the material property input values required for these models were also performed as a

part of this research.

Connection testing showed splitting failures combined with crushing of main member

material and formation of a single plastic moment. Connection resistance increased with

increased loaded edge distance and number of bolts. The allowable shear design value controlled

the National Design Specification Allowable Stress Design (NDS ASD) lateral design value to

the connection design except for one connection configuration with 7D loaded edge distance for

two bolts of ½ inch, where connection design strength values controlled. The displacement limit

decided for the dowel bearing strength test had a direct impact on the predicted TR-12 capacity

values. The capacity resistance calculated by both fracture models increased with increase in

iii

loaded edge distances. The Mode-I fracture energy values directly affected the predicted fracture

model values. The tension perpendicular to grain strength values directly affected the Jensen

model values.

Statistical comparison of 4D and 7D loaded edge distances and LVL-1 and LVL-2

material revealed that Van der Put model had no difference in the calculated to test (C/T) ratios

with respect to different loaded edge distances and materials and the Jensen model predicted the

C/T ratios at 4D to be significantly greater than at 7D and for LVL-1 to be significantly greater

than LVL-2. Van der Put model over predicts at capacity and the C/T values are consistent with

change in loaded edge distance. Jensen model C/T ratios over predicted for single bolt

connection and predicts accurate for two bolt connection with respect to loaded edge distances.

Comparing the two fracture models with a ductile model TR-12 with respect to different loaded

edge distances, material, number and size of bolts, Jensen model best predicted the C/T ratios.

The Van der Put model tended to over predict values, while the TR-12 model had no consistent

trend in C/T ratios, but seemed to be affected inversely by changes in loaded edge distance.

iv

Acknowledgements

This research was possible because of financial support and continuous encouragement given to

me by my committee chair Dr. Daniel P. Hindman, from Department of Wood Science and

Forest Products. I also wish to thank my committee members Dr. Finley A. Charney and Dr.

Joseph R. Loferski, for providing their expertise as needed.

I also would like to extend my thanks to many members of the staff at Brooks Forest Product

Center without the help of whose this project may not have been as successful. Thank you Rick

Caudill, David Jones, Kenny Albert, and Angela Riegel.

I am also thankful to my friends and colleagues who provided a constant encouragement and

boosted my morale throughout my time here at Virginia Tech and made my time away from my

country and family a memorable one.

I wish to thank my grandparents Jawahar D. Patel and Induben J. Patel, parents Chintan J. Patel

and Dipti C. Patel, brother Harshil C. Patel, and my wife Gunjan M. Patel, without whose

continuous support, guidance, encouragement, confidence in me and love, I would not have

reached these heights.

Thank you almighty to give me the strength I posses and for helping and guiding me in my good

and difficult times. Jai Shree Krishna.

v

Table of Contents

Table of Contents -----v

List of Figures -----ix

List of Tables -----xi

1 Introduction

1.1 – Background -------1

1.2 – Practical Applications -------3

1.3 Objectives -------4

1.4 – Significance -------4

2 Literature Review

2.1 – Introduction -------5

2.2 – Wood Connection Design Methodology -------5

2.2.1 – Current Wood Connection Design Methodology Implemented in the

United States -------5

2.2.2 – Development of the Wood Connection Design Methodology -------5

2.2.3 – National Design Specification Methodology -------6

2.2.3.1 – Yield Modes -------7

2.2.3.2 – Technical Report 12 (TR-12) -------9

2.2.3.3 – Dowel Bearing Strength ------10

2.2.3.4 – Spacing requirement ------11

2.2.3.5 – Shear Stress Check ------11

2.2.4 – Allowable Stress Design (ASD) ------12

2.2.5 – Load Resistance Factor Design (LRFD) ------13

2.3 – Fracture Mechanics Modeling of Wood Connections ------14

2.3.1 – Van der Put Model ------16

2.3.2 – Jensen Model ------17

2.3.3 – Eurocode 5 (EC5) ------19

2.4 – Multiple Fastener Connections ------20

2.5 – Previous work by Finkenbinder (2007) ------22

2.6 – Research Objectives ------22

vi

3 Materials and Methods

3.1 – Introduction ------24

3.2 – Materials ------24

3.2.1 – Material Conditioning ------25

3.3 – Sample Size determination ------25

3.4 – Specimen Identification ------26

3.5 – Testing Methods and Order ------27

3.5.1 – Connection Testing ------27

3.5.1.1 – Connection Layout ------28

3.5.1.2 – Connection Test Protocol ------30

3.5.2 – Material Testing ------35

3.5.2.1 – Test Method for Shear Modulus ------36

3.5.2.2 – Test Method for Modulus of Elasticity (MOE) ------38

3.5.2.3 – Test Method for Dowel Bearing Strength ------40

3.5.2.4 – Test Method for Bolt Bending Strength ------42

3.5.2.5 – Test Method for Tension Perpendicular to Grain ------43

3.5.2.6 – Test Method for Mode-I Fracture ------45

3.5.2.7 – Test Method for Moisture Content and Specific Gravity ------47

3.6 – Definitions for Test Properties ------48

4 Results and Discussions: Comparison of Single and Two Bolted LVL Perpendicular to

Grain Connections: TR-12 Model

4.1 Abstract ------50

4.2 Introduction ------51

4.3 Literature Review ------52

4.4 Materials and Methods ------56

4.4.1 Connection Testing ------57

4.4.2 Material Testing ------59

4.5 Results and Discussions ------61

4.5.1 Connection Test (CT Results) ------61

4.5.2 Materials Test Results ------64

vii

4.5.3 NDS ASD Results ------66

4.5.4 TR-12 Capacity Results ------68

4.5.5 Statistical Comparison for TR-12 Model ------70

4.6 Conclusions ------71

4.7 References ------72

5 Results and Discussions: Comparison of Single and Two Bolted LVL Perpendicular to

Grain Connections: Fracture Models

5.1 Abstract ------75

5.2 Introduction ------76

5.3 Literature Review ------76

5.4 Materials and Methods ------80

5.4.1 Material Tests ------81

5.5 Results and Discussions ------86

5.5.1 Material and Property Results ------86

5.5.2 Fracture Model Results ------87

5.5.3 Graphical Comparison of Fracture models and TR-12 model ------90

5.5.4 Eurocode 5 Results ------92

5.5.5 Statistical Comparison for Fracture Models ------93

5.5.6 Statistical comparison between TR-12 and Fracture models ------95

5.6 Conclusions ------96

5.7 References ------97

6 Summary and Conclusions

6.1 Summary ----100

6.2 Conclusions ----100

6.2.1 Connection Test results ----100

6.2.2 Material Test Results ----101

6.2.3 NDS ASD Prediction Result Comparison ----101

6.2.4 EC-5 Prediction Result Comparison ----102

6.2.5 TR -12 Model Capacity Result Comparison ----102

6.2.6 Fracture Model Result Comparison ----102

6.2.7 Comparison between TR-12 and Fracture Models ----103

viii

6.3 Limitations ----104

6.4 Future Work Recommendations ----104

References ----106

Appendix A – Connection Test Load v/s Slip Curves ----111

Appendix B – Connection Test Data ----118

Appendix C – TR-12 Results ----123

Appendix D – Fracture Model Results ----137

Appendix E – Material Property Test Results ----144

ix

List of Figures

Figure 1-1: Practical Application of Connection Perpendicular to Grain ------3

Figure 2-1: a, b, c, d, - the 4 modes for double shear ------8

Figure 2-2: Fracture modes by linear elastic fracture ------15

Figure 3-1 Order of Testing ------27

Figure 3-2 Schematic diagrams for description of the connection detailing ------28

Figure 3-3: Connection Fixtures Steel Side Plate ------29

Figure 3-4: Connection Fixture – (a) Side View, (b) Top View ------30

Figure 3-5: LVDT set-up figure ------31

Figure 3-6 LVDT 1 and 2 Installation Detail ------32

Figure 3-7: LVDT 3 AND 4 Installation Detail ------33

Figure 3-8: LVDT 5 Installation Detail ------33

Figure 3-9: LVDT 6 Installation Detail ------34

Figure 3-10: Figure of the sample locations taken from the connection test specimen ------36

Figure 3-11: ASTM D 198 Torsion Test Setup ------37

Figure 3-12: Three-Point Bending Test Configuration ------38

Figure 3-13: ASTM D 5764-97a, (a) Full Hole Dowel Embedment Strength Specimen,

(b) Dowel Embedment Test Set-Up ------41

Figure 3-14: (a) Diagram of Cantilever Bending Test Method, (b) Bolt Bending Test Set-Up --42

Figure 3-15: ASTM D 193 Tension Perpendicular to Grain Specimen and Test Set-Up ------44

Figure 3-16: Fracture Specimen Dimension ------46

Figure 3-17: Fracture Test Fixture Set-Up ------47

Figure 3-18: Load-Slip Curve, with calculated values ------49

Figure 4-1: Figure 4.1: Schematic diagrams for description of the connection detailing ------57

Figure 4-2: Dowel Bearing Strength: (a) Specimen, (b) Setup ------60

Figure 4-3: Cantilever Bolt Bending set up ------61

Figure 4.4: Failure Types Observed from Connection Testing ------62

x

Figure 5-1: Shear Modulus Testing ------82

Figure 5-2: Modulus of Elasticity Test ------83

Figure 5-3: Tension Perpendicular to Grain Strength Test ------84

Figure 5-4: Mode I Test, (a) Specimen, (b) Specimen Dimension ------85

Figure 5-5: Model Comparisons ------91

xi

List of Tables

Table: 3-1 Testing Data ------26

Table: 3-2: Description of locations where LVDT’s measured displacement ------31

Table: 4-1 Test Plan for Connection testing ------58

Table: 4-2: Failure Modes Observed ------63

Table: 4-3 Connection Test Results ------64

Table: 4-4 Properties for TR-12 Model ------65

Table: 4-5 NDS ASD Lateral Design Values Considering Connection Resistance and

Allowable Shear ------66

Table: 4-6 Tested to Design Capacity Ratios for NDS ASD Lateral Design Values ------67

Table: 4-7 TR-12 Capacity Results ------69

Table: 4-8 C/T Ratio for TR-12 at Capacity ------70

Table: 4-9 Statistical Comparison of C/T Ratios at Capacity ------71

Table: 5-1 Material Property Results ------87

Table: 5-2 Fracture Model Results ------88

Table: 5-3 C/T Ratio for Fracture Models at Capacity ------89

Table: 5-4 Eurocode 5 Characteristic and Design Splitting Capacities ------92

Table: 5-5 Average EC-5 Design Safety Factor Values ------93

Table: 5-6 Statistical comparison of C/T ratios at capacity, considering test variables ------94

Table: 5-7 TR-12, Van der Put and Jensen Model Comparison for Connection Capacity ------95

1

CHAPTER 1: INTRODUCTION

1.1 Background

Wood and wood products have proven to be an essential part of our lives. Wood is used

more by weight than all plastics, metals and cement combined (Eco-link 2001). Engineered

wood products (EWP) efficiently utilize available forest resources and develop superior products

with fewer defects, or distribute these defects to mitigate their effect. Key factors contributing in

the growth of EWP usage are cost-effectiveness, ease of use, environmentally sensitive products,

strength and more predictable properties. (Eco-link 2001). Structural composite lumber (SCL) is

a type of EWP that combines veneer sheets or strands with structural adhesives to form structural

products. SCL includes laminated veneer lumber (LVL), parallel strand lumber (PSL) and

oriented strand lumber (OSL) (Smulski 1997). The most widely used SCL product is LVL used

for beams and headers, hip and valley rafters, scaffold planking, and the flange material for I-

joists. LVL is produced by bonding layers of veneers with adhesives cured under heat and

pressure, such that the veneer layers are parallel to the machine direction.

Market share of LVL was obtained from “Ontario’s Value-Added Wood Products Market

Potential in the U.S. Great Lakes States” from Woodbridge Associates Inc. (2003). Engineered

wood is the largest single group of materials used for structural floors in the USA with a 37%

market share. EWPs, predominantly LVL, dominate the floor beam market having a 43% market

share. A report from APA – The Engineered Wood Assoication (2005) indicates a significant

increase in the total demand and production of LVL, from 51.9 million cubic feet in 1999 to 86.3

million cubic feet in 2004. The above mentioned facts and figures clearly indicate that LVL is an

important building material.

For the continuous usage of SCL products, a detailed understanding of material

properties and behavior is essential. Connections are one of the weakest links in wood

construction and are considered to be a critical part in structural design. A connection consists of

two or more members joined together with one or more mechanical fasteners. Laterally loaded

dowel type fasteners like nails, bolts and screws are the most common components of the

structural connections used in wood. The behavior and properties for the connections in LVL has

not been studied as extensively as in solid wood. In comparison, there is relatively little research

2

for connections loaded perpendicular to the grain, compared to connections loaded parallel to the

grain. Multiple bolted connections are the most commonly used type of connection in the field

today, yet little research data is available on laterally loaded multiple bolt connections

perpendicular to the grain.

As mentioned by Smith and Foliente (2002), research related to bolted connections,

particularly with multiple bolts loaded in perpendicular to the grain direction, is of high priority.

More research should be conducted on such connections to collect more information about their

behavior at capacity. This research would help in validating the application of general dowel

equations, especially connection behavior at capacity. The ductile connection behavior assumed

by the National Design Specification for Wood Construction (NDS) (AF&PA 2005) cannot

explain all connection failures as observed in previous research by Smith et al. (2008) and Snow

et. al (2004a and 2004b). Brittle failure is a common occurrence for dowels loaded perpendicular

to the grain including splitting or crushing. Therefore the use of fracture models to analyze this

failure type is needed. Several authors have developed fracture mechanics models to explain

splitting behavior of wood including the Van der Put model (Van der Put and Leijten 2000) and

the Jensen model (Jensen et al 2003).

The research conducted for the current thesis is a succession and an expansion of the

work done by Finkenbinder (2007) who compared the MSR lumber, LVL and PSL materials

using a single bolted connection loaded perpendicular to grain. Finkenbinder (2007) observed

brittle failure characterized by splitting for specimens loaded at lower edge distances and a

mixed failure characterized by splitting and crushing or splitting and bending of bolt for

specimens loaded at greater edge distances, for all three materials. Also, the predictions for

fracture models were assumed to be reasonably accurate depending on Mode I fracture energy.

Model predictions from the Van der Put and Leijten (2000) model were found to be more stable

and consistent than the other models over the range of different loaded edge distances for all

three materials (Finkebinder 2007). The current thesis conducts testing of two LVL materials

from two different manufacturers with different bolt diameters, different loaded edge distances,

and single and multiple-bolted configurations. This research will provide enhancement of the

knowledge of single and multiple bolted connections loaded in perpendicular to the grain

connections for LVL.

3

1.2 Practical Applications

Figure 1-1 shows a practical application of connections loaded perpendicular to grain (not

LVL). Figure 1-1 (a), shows the load from wood joists being carried by single bolt double shear

connection, where the side members are loaded perpendicular to grain. Figure 1-1 (b) shows the

load from wood joists being transferred to steel I-beam which transfers the load to the

overhanging wood beam, which is loaded perpendicular to grain direction with two rows of two

dowels.

(a)

(b)

Figure 1-1: Practical Application of connection Perpendicular to Grain (not LVL)

4

1.2 Objectives

The objective of this research was to investigate single and two bolted connection

configurations loaded perpendicular to grain using different LVL manufacturers, loaded edge

distances and diameter of bolt.

The goals of this research project include:

1) Measure properties from single and two bolted connections loaded perpendicular to the

grain in double shear.

2) Compare connection resistance to yield based model and design literature including TR-12

and NDS ASD.

3) Compare connection resistance to fracture based models and design literature including Van

der Put & Leijten (2000), Jensen et al. (2003), and Eurocode-5 (ENV 2005-1-1, 2004).

1.3 Significance


priority research area by Smith and Foliente (2002), for the advancement of the LRFD of

connections. The results obtained from the experimental testing will provide information

regarding the behavior of connections at conditions of capacity and yield, and a comparison

between single and two bolted connections for LVL from different manufacturers. Comparison

of the experimental results with the TR-12 general dowel equations and the fracture models will

help in accurately predicting LVL connection behavior. Success in achieving the goals of this

research will provide enhancement of knowledge and information for single and two bolted

connections loaded in perpendicular to the grain connections for LVL and thereby help in

calibrating LRFD parameters on pure reliability basis in future.

5

CHAPTER 2: LITERATURE REVIEW

2.1 Introduction

This literature review summarizes the development of the lateral design methodology for

wood connections. It also explains the methodology used by the National Design Specification

for Wood Construction (NDS) (AF&PA 2005) and the two design formats that the NDS

specifies, allowable stress design (ASD) and load resistance factor design (LRFD). Two fracture

models provide predictions of the resistance at capacity for splitting of perpendicular to grain

connections. Lastly recent research by Finkenbinder (2007) was discussed.

2.2 Wood Connection Design Methodology

2.2.1 Current Wood Connection Design Methodology implemented in the United States

The NDS (AF&PA 2005) is the current standard for designing of the wood structures in

the United States. The designing is based on general dowel equations based on yield theory given

by Johansen (1949) and Larsen (1979). The yield theory assumes that the connection exhibits a

ductile behavior till the capacity resistance is reached. This capacity resistance is characterized

by any of these three failure modes; crushing of the member, yielding of the fastener or a

combination of both crushing and yielding. The splitting or cracking of the wood member, which

is characterized as a brittle failure, can be accounted for by two provisions; fastener spacing

requirements and an additional check of member stresses.

The two design methodologies currently used by the NDS are ASD and LRFD, both of

which depend on the European Yield Model (EYM). The LRFD is based on a “soft conversion”

from ASD and the ASD values are based on 5% offset yield resistance. Due to the observed

advantages of the strength based design over ASD, the interest in capacity based LRFD is

increasing. EYM, yield modes and the factors used by ASD and LRFD methods are explained in

sections 2.2.2 and 2.2.3.

2.2.2 Development of the Wood Connection Design Methodology

The empirical equations obtained from the monotonic experimental testing of bolted

timber connections by Trayer (1932) for laterally loaded single fastener dowel type connections

proved to be significant in calculating the design values of bolted connections and also in

6

introducing the idea of design based on the proportional limit of the connection load

displacement behavior. Geometric parameters including the end distance, edge distance and bolt

spacing were taken into consideration by Trayer (1932) to prevent premature splitting before

reaching the design level resistance.

The European Yield Model (EYM) was introduced by Johansen (1949). The principle

assumptions of the model were an ideal elastic-plastic behavior of steel dowel and wood

connection members, laterally loaded connectors with no gap present between the members, and

negligible friction. Failures consisted of either an embedment failure in the wood surrounding the

dowel, one or two plastic hinges forming in the dowel, or a combination of two mechanisms

(Finkenbinder 2007).

Many researchers in the field of lateral connection design have used these theories and

their work has proved the accuracy of these two theories. As cited by Finkenbinder (2007), work

which supports Trayer (1932) includes Doyle and Scholten (1963), and Soltis et al. (1986). Work

supporting Johansen (1949) includes McLain and Thangjitham (1983), Aune and Patton-Mallory

(1986) and Soltis and Wilkinson (1987).

Also, as cited by Ramskill (2002), the first significant testing of lateral connections was

done by Newlin and Gahagan (1938) using lag screws, and the lateral yield design for the 1991

NDS based on 5% offset yield was initially proposed by Harding and Fowkes (1984) and Patton-

Mallory (1989) for use with bolted connections.

2.2.3 National Design Specification Methodology

The EYM is the basis for the current NDS connection design methodology, for both ASD

and LRFD. The design provisions for mechanical connections and dowel type fasteners are

discussed in Chapters 10 and 11 of the NDS (AF&PA 2005).

The adjusted reference lateral design value (Z’) is used for comparison to the imposed

connection loads. The Z’ value is obtained by multiplying the reference lateral design value (Z)

with the applicable adjustment factors explained in Table 10.3.1 of the NDS (AF&PA 2005).

The Z value is the minimum load value obtained from the applicable yield limit equations for

different yield modes in Table 11.3.1A of the NDS (AF&PA 2005). In the case of double shear,

there are four yield mechanisms mentioned: Mode Im, Mode Is, Mode III and Mode IV. The

different yield modes for double shear connections are shown in section 2.2.3.1.

7

As mentioned previously, minimum calculated load from the yield equations is the

governing load and the mode of connection failure corresponding to this load is the expected

mode of failure of the specimen at yield, provided the spacing requirements are accurately

followed. It should be noted that the predicted yield modes for single fastener connections with

sufficient end and edge distances are indicative of connection yielding but may not represent

behavior at the ultimate load or damage observed at failure. Typical failures observed can

include “Splitting of wood along the line of fasteners, formation of a shear plug, fastener shear,

and fastener withdrawal” (AF&PA 1999).

2.2.3.1 Yield Modes

There are four yield modes with six yielding mechanisms for single shear failure and

three yield modes with four yielding mechanisms for double shear failure. Double shear means

the member is subjected to shearing stress along two planes. The double shear failure mechanism

consists of Mode Im, Mode Is, Mode IIIs and Mode IV. Figure 2-1 (a) and (b) shows the failure

Mode Im and Is that represents bearing-dominated yield of wood fibers in contact with the

fastener in either the main or the side member(s), respectively. Figure 2-1 (c) shows Mode IIIs

failure that represents fastener yield in bending at one plastic hinge point per shear plane, and

bearing dominated yield of wood fibers in contact with the fastener in the side member(s), and

part (d) shows Mode IV failure that represents fastener yield in bending at two plastic hinge

points per shear plane, with limited localized crushing of wood fibers near the shear plane

(AF&PA 2005).

8

MODE Im (a) MODE Is (b)

MODE IIIs (c) MODE IV (d)

Figure 2-1: a, b, c, d, - the 4 modes for double shear

The yield limit equations for the double shear as mentioned in the NDS Table 11.3.1A

are as follows:

MODE Im: d

emm

R

FDlZ = MODE Is:

d

ess

R

FDlZ

2=

MODE IIIs: de

ems

RR

FDlkZ

)2(

2 3

+= MODE IV:

)1(3

22 2

e

ybem

d R

FF

R

DZ

+=

Where,

2

2

33

)2(2)1(21

sem

eyb

e

e

lF

DRF

R

Rk

++

++−=

D = dowel diameter, (inch)

Fyb = dowel bending yield strength, (psi)

Rd = reduction term, (Table 11.3.1B, NDS AF&PA 2005)

Re = Fem/Fes

lm = main member dowel bearing length, (inch)

ls = side member dowel bearing length, (inch)

Fem = main member dowel bearing strength, (psi)

Fes = side member dowel bearing strength, (psi)

9

The above mentioned equations are based on the assumptions that there is no gap and no

friction between the faces of the connected members, the load acts perpendicular to the axis of

dowel, and edge distances, end distances, spacing and penetration are in accordance with the

section 11.1.2 of the NDS 2005.

2.2.3.2 Technical Report 12 (TR-12)

General Dowel Equations for Calculating Lateral Connection Values - Technical Report

12 (AF&PA 1999), which is commonly referred to as TR-12, is an expanded form of NDS

general dowel equations (AF&PA 2005). Equations from TR-12 are able to predict connection

loads at the proportional limit, 5% offset yield load and at capacity for all yield modes. The

equations presented in TR-12 allow for inter member gaps and fastener moment resistance. TR-

12 does not consider the end fixity (resistance to rotation provided at the ends of the dowel) and

effect of friction between the connection members. TR-12 assumes that the dowel remains in

equilibrium and that the dowel is under uniform bearing along the dowel length. In order to

obtain the factored allowable design load based on the 5% offset, the critical governing load (P,

the minimum load determined from the equations) is divided by the applicable reduction terms as

provided in Table 2 of TR-12 (now equivalent to the Z term from the NDS), which is then

multiplied by the adjustment factors including load duration, wet service, temperature, size, flat

use, incising, stability, repetitive member, curvature, shear stress, buckling stiffness and bearing

area, as mentioned in the NDS (Ramskill 2002) and (Finkenbinder 2007).

The double shear equations from TR-12 are shown below:

mmlqP =Im (Eqn: 2-1)

ssIs lqP 2= (Eqn: 2-2)

)2

1

4

1(

)4

)(2

1

4

1(4)

2()

2(

2

22

ms

mss

ms

s

IIIs

qq

Mlq

qqg

lg

l

P

+

−−+−++−−

= (Eqn: 2-3)

)2

1

2

1(

))(2

1

2

1(42

ms

ms

ms

IV

qq

MMqq

gg

P

+

−−+−+−

= (Eqn: 2-4)

10

Where,

P = nominal lateral connection value, (lbs)



qs = side member dowel bearing resistance = FesD, (lbs. /inch)

qm = main member dowel bearing resistance = FemD, (lbs./inch)



g = gap between members, (inch)

D = dowel shank diameter, (inch)

Fb = dowel bending strength, (psi)

Ds = dowel diameter at maximum stress in side member, (inch)

Dm = dowel diameter at maximum stress in main member, (inch)

Ms = side member dowel moment resistance, (inch-lbs.) = Fb(Ds3/6)

Mm = main member dowel moment resistance, (inch-lbs.) = Fb(Dm3/6)

2.2.3.3 Dowel Bearing Strength

One of the variables used in the NDS and TR-12 is the dowel bearing strength of the

main and side members. Due to the importance of bearing strength in determining the connection

strength, ample research has been concentrated on quantifying the factors affecting it. Factors

include “span/depth ratio, bearing surface roughness, angle between loading and grain direction,

loading rate and/or duration, bolt angle with respect to load direction, bolt hole oversize, specific

gravity, and moisture content have been investigated” (Smart 2002).

For dowel diameter greater than 0.25 inch, the dowel bearing strength loaded

perpendicular and parallel to the grain can be calculated from the Equation 2-5 (a) & (b),

according to the section 11.3.2 of the NDS (AF&PA 2005).

Fe┴ = 6100G1.45

/ (D) 1/2

(Eqn: 2-5 (a))

Fell= 11200G (Eqn: 2-5 (b))

Where,

G: specific gravity or Equivalent Specific Gravity (ESG)

D: dowel diameter,(inch)

11

The Equivalent Specific Gravity (ESG) is used for SCL products, in Equation 2-5 (a) &

(b). To obtain the ESG value, the bearing strength values from the dowel bearing strength test

and the dowel diameter are used in the Equation 2-5 (a) & (b) and back calculation was

performed for obtaining the corresponding specific gravity (Johnson and Woeste 2000).

2.2.3.4 Spacing Requirements

Spacing requirements mentioned in the NDS that prevents the premature splitting of the

connection include edge distance, end distance and spacing between fasteners. These are of

utmost importance pertaining to our research of single and multiple bolt arrangements with

variable bolt sizes. These limitations as mentioned in the NDS for perpendicular to the grain

direction are in terms of the dowel diameter (D) and are as follows:

� Edge Distance: “Distance measured from edge of the member to the center of the nearest

fastener, measured perpendicular to grain” (AF&PA 2005).

• Loaded Edge – 4D : (edge in the direction towards which the fastener is acting)

• Unloaded Edge – 1.5D : (edge opposite to the loaded edge)

� End Distance: “Distance measured parallel to grain from the square-cut end of a member to

the center of the nearest bolt” (AF&PA 2005).

• 4D

� Spacing requirements for fasteners in a row: “Distance between centers of fasteners

measured along a line joining their centers” (AF&PA 2005).

• 3D

The NDS section 11.1.2.2 states that the hole drilled must be within the range of 1/32

inch and 1/16 inch larger than the bolt diameter, and the bolt should not be forcibly driven into

the holes as it can damage the hole.

2.2.3.5 Shear Stress Check

When load is applied perpendicular to grain in a wood member with a reduced cross-

section (such as bolt hole), an additional shear stress check must be performed as defined by

NDS section 10.1.2 (AF&PA 2005). For beam loaded perpendicular to grain connections, the

adjusted shear design check as mentioned in the section 3.4.3 of the NDS is necessary. For

instances when the connection is located at a distance less and greater than five times the depth

12

of the member, from the end of the member, the Equation (2-6a) and (2-6b) are used to find out

adjusted design shear value respectively (AF&PA 2005).

2

3

2

′=

′

d

dbdFV e

evr (Eqn: 2-6a)

′=

′evr bdFV

3

2

(Eqn: 2-6b)

Where,

Vr' = adjusted design shear, (lbs.)

Fv' = adjusted shear design value parallel to grain, (psi.)

b = width of member, (inch)

de = depth of the member, less the distance from the unloaded edge of the member to the center

of the nearest bolt, (inch)

d = depth of member, (inch)

2.2.4 Allowable Stress Design (ASD)

Allowable stress design method uses a factor of safety approach, where the actual load is

compared to a stress level below the ultimate level and the loads. The method is used widely in

the design of wood structures currently, but a shortcoming of using this method is that it is highly

conservative and there is no defined level of reliability.

The adjusted reference lateral design values (Z’) for allowable stress design are calculated

by determining the reference lateral design value (Z), and multiplying it by adjustment factors C

followed by unique subscripts. The equation for the calculation is as follows:

Z’ = Z(CD)(CM)(Ct)(Cg)(C∆)(Ceg)(Cdi)(Ctn) (Eqn: 2-7)

Where,

Z’ = adjusted reference lateral design value, (lbs.)

Z = reference lateral design value, (lbs.) (min. Z - Table 11.3.1A AF&PA NDS-2005)

CD= load duration factor CM = wet service factor

Ct = temperature factor Cg = group action factor

C∆ = geometry factor Ceg = end grain factor

Cdi = diaphragm factor Ctn = toe-nail factor

13

The adjusted design shear parallel to the grain value (Fv’) is determined by multiplying

the tabulated shear parallel to the grain value (Fv) to the applicable adjustment factors obtained

from Table 4.3.1 of the NDS. The equation to calculate the adjusted design shear parallel to the

grain value is given as follows (AF & PA 2005),

Fv’ = Fv (CD)(CM)(Ct)(Ci) (Eqn: 2-8)

Where,

Fv’ = adjusted design shear parallel to grain value, (psi.)

Fv = tabulated shear parallel to grain value of the member, (psi.)

(These values were obtained from manufacturer’s literature for LVL)

CD = load duration factor

CM = wet service factor

Ct = temperature factor

Ci = incising factor

2.2.5 Load Resistance Factor Design (LRFD)

Load resistance factor design (LRFD) is a reliability based design. Unlike ASD, LRFD

does not use the actual loads, but factored loads. Strength values at the ultimate load are

compared to the factored loads. A time factor λ is also applied to the resistance value. The main

advantage of using this method is that it has a targeted reliability and sometimes can lead to

smaller member sizes than as calculated by ASD for certain loading situations.

The adjusted reference lateral design value (Z’), for reliability based design is calculated

by determining the reference lateral design value Z, and multiplying by adjustment factors C

followed by unique subscripts some of which are the same as in ASD and also other factors like

resistance factor (φz) and format conversion factor (KF) as shown in the equation below. The

equation for the calculation is as follows:

Z’ = Z(KF)(φz)(λ) (CM)(Ct)(Cg)(C∆)(Ceg)(Cdi)(Ctn) (Eqn:2-9)

Where,



φz = resistance factor = 0.65

KF = format conversion factor = 2.16/ φz = 3.32

14

λ = time effect factor

CM, Ct, Cg, C∆, Ceg, Cdi, Ctn, = same adjustments as mentioned for ASD in Eqn: 2-7

The adjusted LRFD shear value (Fv’) is determined by multiplying the tabulated shear

parallel to the grain value (Fv) to the applicable adjustment factors obtained from Table 4.3.1 of

the NDS. The equation to calculate the adjusted LRFD shear value is given as follows (AF & PA

2005):

Fv’ = Fv(KF)(φv)(λ)(CM)(Ct)(Ci) (Eqn: 2-14)

Where,

Fv’ = adjusted LRFD shear value (psi)

Fv = tabulated shear parallel to grain value (psi)


φv = shear resistance factor = 0.75

KF = format conversion factor = 2.16/ φv = 2.88

CM, Ct, Ci = same adjustments as mentioned for ASD in Eqn: 2-8

The difference between LRFD and ASD shear values is a ‘soft-conversion’ in the form of

the format conversion factor, KF/ φv (AF&PA 2005 & Finkenbinder 2007).

2.3 Fracture Mechanics Modeling of Wood Connections

The study of the formation and growth of cracks in materials is the basis of fracture

mechanics (Smith et. al. 2003). Fracture mechanics modeling has proved to be an effective tool

in predicting the brittle failure of cracked components under applied loads. Fracture mechanics

has been effectively applied to homogeneous isotropic materials, and has not been developed

fully for orthotropic materials, but may be useful for describing orthotropic materials including

wood and other fiber reinforced composites (Smith et al. 1999).

The three possible fracture modes that are considered include: Mode-I Opening/Tension,

Mode-II In-Plane Shear, and Mode-III Out of Plane Shear, and are shown in the Figure 2-2.

Mixed mode combinations of the three modes are allowed and it is usually assumed that the

material exhibits linear elastic behavior untill fracture occurs. (Finkenbinder 2007)

15

MODE-I MODE-II MODE-III

Opening/Tension In Plane Shear Out of Plane Shear

Figure 2-2: Fracture modes by linear elastic fracture

Failure of dowel joints under the influence of loads perpendicular to grain are either

characterized by bending of the fastener and/or embedment of the fastener in to the wood, or a

brittle failure that is characterized by splitting (also known as cracking) of the wood. The ductile

failure is well understood and accounted for by the European Yield Model (EYM), but brittle

failure has received little attention (Jensen 2003).

In designing wood structures, connection design is of utmost importance and failure of

structural joints must be studied. Brittle failure is characterized by splitting/cracking of the wood

due to high localized stress concentrations near the hole of the bolted connection. The crack

initiates at the boundary of the bolt hole and propagates parallel to the grain. The crack starts and

propagates from these holes, which leads to brittle fracture once the crack reaches an unstable

stage of development (Smith et al. 1999).

Many researchers have applied principles of fracture mechanics for predicting the

capacity resistance achieved before splitting occurs. Linear elastic fracture mechanics (LEFM)

theory and quasi nonlinear fracture mechanics theory has been used for the development of

simpler models. The strain energy rate method based on the Griffith theory of system energy

balance, and the stress intensity factor method which focuses on the distribution of local stresses

near to the crack tip, are two common approaches of LEFM (Finkenbinder 2007).

16

Two models, one using LEFM and one using quasi nonlinear fracture mechanics (based on

beam-on-elastic foundation (BEF)) have been presented and used to model the capacity

resistance of wood and wood composite materials.

2.3.1 Van der Put Model

Van der Put and Leijten (2000) modeled wood connections loaded perpendicular to grain

by dowel joints of beams. The model was based on several assumptions including neglecting

normal forces in the cross section of member at the location where stable splitting occurred.

Crack propagation was defined as the loss of potential energy due to splitting being equal to the

required energy for crack formation. Fracture energy, Gf, must be of sufficient magnitude to

propagate the crack in both the length and the width direction of the beam, resulting in stable

crack propagation (Van der Put and Leijten 2000). The work by Van der Put and Leijten (2000)

will referred to as the Van der Put model for simplicity.

The general equation for splitting of the beam as derived by Van der Put and Leijten

(2000) is as follows:

( ))1(6.0 α

α

−= f

fGG

hb

V (Eqn: 2-16)

Where,

α = he / h = location of the dowel with respect to the loaded edge and the beam height

b = beam width, (mm)

he = distance of the most distant fastener from the loaded edge, (mm)

h = beam height, (mm)

G = shear modulus of the material, (N/mm2)

Gf = fracture energy, (N/mm)

Vf = the maximum shear force at fracture, (N)

Jensen (2003) noted that the additional analysis, including the normal forces at the

cracked section of the beam, have shown very little change in the model and hence justify the

assumption of neglecting those normal forces in the Van der Put model. Also, a simplified

assumption of Gf based on only Mode I fracture, instead of assuming mixed mode of Mode I and

Mode II interaction was a reasonable approximation by Schoenmakers (2006).

17

An alternative form of equation for the Van der Put model is as follows:

α

α

−=

11C

hb

V f where,

6.01

fGGC = (Eqn: 2-17)

As cited by Finkenbinder (2007), results from the research of Ehlbeck et al. (1989),

Ballerini (1999), Reshke (1999) and Reffold et al. (1999) who have tested nails and dowels

loaded perpendicular to grain connection, with steel-timber-steel bolted connections and punched

metal plate connections in simply supported beams, were used to calibrate the C1 value such that

C1 = 10 N/mm1.5

(Van der Put and Leijten 2000). So the Equation 2-17 can be simplified to

Equation 2-18 assuming a standard relationship for G, Gf, which are material properties and

change for different materials.

α

α

−=

110

hb

V f (Eqn: 2-18)

Snow et al. (2004b) measured laminated strand lumber (LSL) connections and found that

the Van der Put model was relatively accurate. The LSL connections failed in bending rather

than splitting as observed when similar analysis was performed with LVL and PSL (Snow et al.

(2004a). Snow et al. (2004 a,b) used a dowel of ¾ inch and the main member depth was 3-1/2

inch thereby lowering down the loaded edge to 2.33D, which is much less than the required

minimum considerations, equal to 4D, as mentioned in the NDS (AF&PA 2005).

2.3.2 Jensen Model

Jensen (2003) presented a linear elastic fracture model for calculation of splitting failure

load for dowel type fastener joints loaded perpendicular to grain similar to the Van der Put model

previously described, but included the normal forces in cracked parts of the beam. Jensen (2003)

found that for two joints spaced along the grain, the model predicted either the same failure load

(for cracks merged between the joints) or twice the failure load (for cracks not yet merged

between the joints). However, Jensen (2003) found that these results were not valuable as per the

test data considered.

Jensen et al. (2003) developed a model based on the beam-on-elastic foundation (BEF)

theory. The model can be “applied to plates with edge dowels, to beams with dowels, and to

beam spice joints made of rods glued in a long grain” (Jensen et al. 2003). The model provided a

complete derivation using conventional stress method, finite element solution, and experimental

18

validation. A Timoshenko beam having a finite length and linear elastic springs support, which

were connected to stiff foundation, was the basis of this model. The perpendicular to the grain

strength and fracture performance of the wood was modeled with the help of these springs. The

non-linear damage and fracture performance of wood is presented as “a linear response that is

equivalent in terms of peak stress, ft, and fracture energy dissipation, Gf . . . Failure was assumed

to occur when the maximum stress, equaled the tensile strength perpendicular to grain, ft”

(Jensen et al. 2003). The model equations for failure load of a single dowel and two dowels in a

row, loading a beam perpendicular to grain are as follows (Jensen et al. 2003):

efLEFMPP hGGbPP3

20, µµ == (Eqn: 2-19)

Where,

1

12

+

+=

ζ

ζµ and

2

2))(

3

5(

te

f

fh

EG

E

G=ζ

Where,

b = beam width, mm.


G = shear modulus of the material, N/mm2

Gf = fracture energy perpendicular to grain (mode I), N/mm

E = modulus of elasticity of the material, N/mm2

ft = tensile strength perpendicular-to-grain, N/mm2

PP, LEFM = the failure load as a LEFM solution, N

PP = the failure load, N

For determining the accuracy of the derivation based on BEF theory, Jensen et al. (2003)

performed a finite element analysis of a ‘symmetrical beam with one or more dowels’. The

model also found a good correlation between the theoretical predictions and experimental results

when applied to glulam beams with lower span:depth ratios, and plate tests, performed by

Yasumura (2001), Quenneville and Mohammad (2001), and Kasim and Quenneville (2002).

However, it was noted that the model over predicted the results for larger loaded edge distances

(Jensen et al. 2003).

19

2.3.3 Eurocode 5 (EC5)

The European design code Eurocode5 (EC5) applies to design of buildings and works in

timber in civil engineering, and concerns with the requirements for mechanical resistance,

serviceability, durability and fire resistance of timber structures. Characteristic and design

splitting capacity is similar to the reference lateral design value (Z, without modification factors)

and adjusted lateral design value (Z’, with modification factors) respectively. The design

splitting capacity value is used for design purpose. EC5 has a specific check of the splitting

capacity for perpendicular to the grain connections in softwoods denoted in Section 8, as

Equations 8.4 and 8.5 and are as follows (ENV 2005-1-1, 2004):

h

h

hbwF

e

e

Rk

−

=

1

14,90 (Eqn: 2- 20)

Where, w = maximum of

35.0

100

plw or 1, for punched metal plate fasteners and

w = 1, for all other fasteners

Where,

F90,Rk = the characteristic splitting capacity, (N)

w = modification factor for fastener type

he = loaded edge distance of the most distant fastener, (mm)

h = member height, (mm)

b = member width, (mm)

wpl = width of the punched metal plate fastener parallel to the grain, (mm)

Section 2.4.3 of EC5 relates the characteristic value to the design value, along with

accounting for the material type, load duration, and moisture content effects (ENV 2005-1-1,

2004):

=

M

Rk

Rd

FkF

γ90

mod,90 (Eqn: 2-21 )

Where,

F90,Rd = design splitting capacity, (N)

γM = partial factor for material properties = 1.2 for connections

20

kmod = modification factor considering load duration and service moisture content

= 0.9 for LVL under a short term load with moisture content not exceeding 20%

2.4 Multiple Fastener Connections

Multiple bolted connections are most commonly used type of connection in the field

today. The strength of a multiple bolted connection is calculated by summing the single fastener

strength values after multiplying by a modifying factor called “Group Action Factor, Cg”. The

strength of the multiple fasteners connection depends on the number of fasteners in a row, the

spacing of fasteners, the load slip modulus for the connection, the modulus of elasticity and gross

cross sectional area of main and side members, and whether the rows are in a symmetric or

staggered pattern.

Soltis and Wilkinson (1987) state “The NDS modifying factor for wood side members’

perpendicular to the grain, however is larger than that from experimental results. It appears that

when NDS values were derived, the same modulus of elasticity was used for both grain

directions because the longitudinal modulus is much greater than the radial or tangential modulus

of elasticity for wood, the resulting NDS values are too high”. Soltis and Wilkinson (1987) also

mention that there exists no theory or experimental data to determine the load distribution to

more than one row of bolts, or for recommending staggered or symmetric bolt patterns for

multiple rows of bolts.

The Cg factor was formulated by Zahn (1991) and Section 10.3.6 of the NDS (AF&PA

2005), specifies the following equation for calculating it. For a single fastener, Cg is equal to 1,

otherwise is calculated as:

]1

1][

]1)1)(1[(

)1([

2

2

m

R

mmmRn

mmC EA

nn

EA

n

g−

+

+−++

−= (Eqn: 2-22)

Where,

Cg = 1 for dowel type fasteners with D < ¼ inch

n = number of fasteners in a row

REA = the lesser of )(mm

ss

AE

AEor )(

ss

mm

AE

AE

Em = modulus of elasticity of the main member, psi

21

Es = modulus of elasticity of the side member, psi

Am = gross cross-sectional area of the main member, in2

As = sum of the gross cross-sectional area of the side members, in2

12 −−= uum , ]11

[2

1ssmm AEAE

su ++= γ

s = center to center spacing between fasteners in a row, inch

γ = load slip modulus for a connection, lbs. /inch = (270,000)(D1.5

) for dowel type fasteners in

wood-to-metal connections.

D = diameter of bolt or lag screw, inch

Snow et al. (2005) conducted connection test on two type of arrangements of the multiple

bolts, one with 2 rows and 1 bolt and another with 2 rows and 2 bolts. Diameter ¾ inch and 3/8

inch, respectively, of grade 8 bolts were used to ensure no plasticity (i.e. to prevent Mode III and

Mode IV from occurring). It was observed that the former arrangement carried higher load with

low deflection as compared with the later arrangement. Both the model arrangements showed

brittle failure along the longitudinal direction of the grain.

Wilkinson (1986) states that, for any given connection, there exists a unique load

distribution amongst the bolts, which is very difficult to accurately predict due to large

variability effects in single fastener force deformation behavior and fabrication tolerances on the

load distribution. Hence, Wilkinson (1986) suggests that the present methods for designing

multiple bolted connections may be non-conservative as any one bolt might be carrying majority

of the load and any bolt could be drilled improperly causing it not to transmit the load (Billings

2004).

Albright (2006) mentions that Wilkinson (1980) and others have noted various

limitations to Lantos (1969) method, which forms the basis for the calculation of Cg in the NDS.

The limitations were Lantos’s assumption of linear elastic joint behavior which is rarely the case

in wood connections and that Lantos’s work did not account for the load redistribution and

variable load-slip behavior among fasteners (Albright 2006).

22

2.5 Previous work by Finkenbinder (2007)

The work of Finkenbinder (2007) considered a beam monotonically loaded perpendicular

to grain at mid-span with a single bolt laterally loaded in double-shear. Finkenbinder (2007)

compared the experimental test results with theoretical predictions from the three models: TR-

12, Van der Put, and Jensen model. Finkenbinder (2007) performed 120 double shear connection

tests and 550 material property tests for property input values for the three models. The three

variables considered for the research were span:depth ratio (3:1, 5:1, 10:1), loaded-edge

distances (4D, 7D, 10D- where D is the dowel diameter), and main member material (southern

pine machine stress rated (MSR) lumber, LVL and PSL).

Finkenbinder (2007) observed brittle failure characterized by splitting for specimens

loaded at lower edge distances and a mixed failure characterized by splitting and crushing or

bending for specimens loaded at greater edge distance, for all three materials. Also, it was

observed that in most of the cases, TR-12 was found to be more accurate than the fracture

models and that all the three models over predicted the connection capacity at low loaded edge

distance. Results from Finkenbinder (2007) showed that the calculated to test (C/T) ratio with

different loaded edge distances, were found to be more stable and consistent for Van der Put

model than the other models. For all three materials and the variable span:depth ratio had a

negligible effect on both connection and model performance.

2.6 Research Objectives

The research conducted for the current thesis is a succession and an expansion of the

work done by Finkenbinder (2007). The current thesis conducts testing of LVLs from two

different manufacturers using variable bolt diameters, different loaded edge distances, and single

and multiple-bolted configurations.

In contrast to the application of reliability concepts in the design of wood members by

countries like United States and Canada, none of the countries have yet used structural reliability

concepts in derivation or calibration of design equation for joints as the level of safety cannot be

accessed except for simple problems, and hence LRFD of joints still remains as a soft conversion

from the ASD format (Smith and Foliente 2002).

In order to have purely reliability based design of connections, a better understanding of

connections at its capacity is necessary. Research by Finkenbinder (2007), Smart (2002), Snow

23

et al. (2004a and 2004b) have demonstrated the relationship of capacity resistance to current

LRFD predicted resistance, with variables including dowel diameters, member species, member

thickness, and loaded edge distance.


priority research area by Smith and Foliente (2002), for the advancement of the LRFD of

connections. Success in achieving the goals of this research will provide enhancement of

knowledge and information for single and multiple bolted connections loaded in perpendicular to

the grain connections for LVL and thereby help in calibrating LRFD parameters on pure

reliability basis in future.

The objective of this research was to investigate single and two bolted connection

configurations loaded perpendicular to grain using different LVL manufacturers, loaded edge

distances and diameter of bolt.

The goals of this research project include:

1) Measure properties from single and two bolted connections loaded perpendicular to the

grain in double shear.

2) Compare connection resistance to yield based model and design literature including TR-12

and NDS ASD.

3) Compare connection resistance to fracture based models and design literature including Van

der Put & Leijten (2000), Jensen et al. (2003), and Eurocode-5 (ENV 2005-1-1, 2004).

24

CHAPTER 3: MATERIALS AND METHODS

3.1 Introduction

This section discusses the materials and the methodology used in this research. Two types

of LVL were used for this research. All testing was conducted in the Wood Engineering

Laboratory of the Brooks Forest Product Laboratory at Virginia Tech. Connection testing of

single and double bolted connections loaded perpendicular to grain was performed. Variables

included main member LVL, number of bolts, loaded edge distance, and bolt diameter.

Experimental connection results were compared to the TR-12, Van der Put, and Jensen models.

In order to generate model results, a series of material property tests were conducted. Material

testing included the following tests: shear modulus (G), modulus of elasticity (E), dowel bearing

strength, dowel bending strength, Mode I fracture energy, tension perpendicular to the grain

stress, moisture content and specific gravity.

3.2 Materials

The materials tested for this research were LVL from two different manufacturers. The

first LVL was from Georgia Pacific known as GP Lam LVL® which was rated as 2.0E and was

made from yellow poplar (Liriodendron tulipifera) and southern pine (Pinus spp.) veneers (ICC-

ES 2008b), and was designated as LVL-1 for this research. The dimensions of LVL-1 were 1.75

inch thick by 7.25 inch wide. The second LVL, designated as LVL-2, was from Boise known as

VERSA-LAM® which was rated as 3100f-2.0E and was made from southern pine (Pinus spp.)

and eucalyptus (Eucalyptus spp.) veneers, where the majority of the material was southern pine

(ICC-ES 2008a and Finkenbinder 2007). The dimensions of LVL-2 were 1.5 inch thick by 7.25

inch wide.

Bolts used for testing were of diameters ½ inch and 3/8 inch, 4.25 inches long, low

carbon steel, SAE J429 Grade 2 hex head bolts. The minimum tensile yield strength (Fe) for SAE

(Society of Automotive Engineers) bolts is listed as 74,000 psi (Bickford 1998). All bolts were

ordered together from the supplier to ensure that all were from the same batch and thereby

minimize the chances of variation in the bolts.

25

3.2.1 Material Conditioning

All test samples were kept in an environmental chamber for a period of at least 3 weeks

before testing. The environmental chamber condition were maintained at 65% + 1% relative

humidity (RH) and 68○F + 1.8

○F to reduce variability in moisture content. The specimens were

conditioned until the period of testing.

Bolt holes in the specimen to be tested were drilled within 24 hours of the connection

testing. The size of the holes drilled was 9/16” and 7/16” for the 1/2” and 3/8” bolts respectively,

so as to provide an over sizing of 1/16”.

3.3 Sample Size Determination

The formula indicated below from ASTM D 2915-03 (ASTM 2005f) was used for

calculating the number of specimens for each test. A coefficient of variation (COV) of 10% was

considered. This was higher than the COV of 9.4%, maximum obtained by Finkenbinder (2007)

for LVL. The sample size of 10 was obtained with over 85% confidence, after using the

following equation:

� � � ��.��

�.�� (Eqn: 3-1)

Where,

η = sample size

CV = Coefficient of Variation, s/X

s = Standard Deviation of Specimen Values

X= Specimen Mean Value

t= value of the t-static from Table 1 (ASTM D 2915)

Table 3-1 shows the test plan for the connection testing and the number of specimens

used for a particular set of variables. The length of each specimen was 28 inches, including a 3

inch for bearing area on either end of the specimen in accordance with 3:1 span to depth ratio.

The minimum spacing between the bolts for multiple bolted connections was three times the

diameter of the bolt used (3D) as specified in the NDS (AF&PA 2005).

26

Table 3-1 Testing Data

SET Number

of Rows

Number

of Bolts

Loaded Edge Distance Bolt Diameter TOTAL

LVL 1 Inch inch

L1-1 4D 2 1/2 10

L1-2 1 1 1.5 3/8 10

L1-3 7D 3.5 1/2 10

L1-4 2.625 3/8 10

L1-5 4D 2 1/2 10

L1-6 1 2 1.5 3/8 10

L1-7 7D 3.5 1/2 10

L1-8 2.625 3/8 10

TOTAL 80

LVL 2

L2-1 1 1 7D 3.5 1/2 10

L2-2 4D 2 1/2 10

L2-3 1 2 1.5 3/8 10

L2-4 7D 3.5 1/2 10

L2-5 2.625 3/8 10

TOTAL 50

GRAND

TOTAL 130

3.4 Specimen Identification

A specific identification procedure was developed and followed to clarify the different

test variables. The variables considered were LVL manufacturer, number of fasteners used,

loaded edge distance, and fastener size.

The first identifier was for material type, L1 and L2 for LVL-1 and LVL-2, respectively.

The second identifier was for number of bolts (fasteners), 1 or 2. The third identifier was the

loaded edge distance in terms of bolt diameter, 4D or 7D. The fourth identifier was the bolt size

which is ½ inch (I) or 3/8 inch (II) and the fifth identifier was specimen number 1 to 10. For

example; L1-2-4D-II-5, would be a sample of LVL-1 with two bolts in a row at a loaded edge

distance of 4D, with 3/8 inch size bolts and specimen number 5.

27

3.5 Testing Methods and Order

The connection and material testing were carried out in a specific order as displayed in

the flowchart below (Figure 3-1). The shear modulus (G) and modulus of elasticity (E) tests were

performed on 86 inch long specimens to satisfy the minimum span: depth requirement of 8:1.

Specimens of 28 inches were then cut from the E and G tested specimen for connection testing.

After the connection testing was conducted, the specimens for testing the dowel bearing strength,

fracture energy, tensile strength perpendicular to grain, moisture content and specific gravity

were then taken from the specimens tested for connection testing. Separate dowel bending

strength tests were conducted on a group of bolts obtained from the same source as the bolts used

in connection testing.

Figure 3-1 Order of Testing

3.5.1 Connection Testing

Connection testing was carried out as outlined in ASTM D 5652-95, Standard Test

Methods for Bolted Connections in Wood and Wood-Based Products (ASTM 2005i). Table 3-1

provides a brief description of testing variables considered for this research. Details regarding the

size and nomenclature of these specimens can be found in sections 3.3 and 3.4 of this chapter.

The connection testing consisted of displacement controlled monotonic compressive loading of a

steel-wood-steel double shear connection at mid-span of a simply supported beam.

Dowel Bending

Strength (Fb)

Connection

Tests

Modulus of

Elasticity (E)

Shear Modulus

(G)

Tensile Strength

Perpendicular to

Grain (ft)

Moisture Content

(MC) & Specific

Gravity (SG)

Fracture Energy

(GIf)

Dowel Bearing

Strength (Fe)

28

3.5.1.1 Connection Layout

Figure 3-2 defines the loaded and unloaded edge distances, span, overall length,

connection layout and detailing. The simply supported specimens were loaded at mid-span with

steel side members connected to a top bearing plate, which transmits the load applied by the

MTS universal testing machine.

Figure 3-2 Schematic diagrams for description of the connection detailing

Where, 1- Support Bearing Plates, 2- Bolt, 3- Steel Side Plate, 4- Top Bearing Plate, 5- MTS

Load Head, 6- Span, 7- Over All Length, 8- Loaded Edge Distance, 9- Unloaded Edge distance,

10- Load Acting Point, 11- Depth

29

As shown in Figure 3-2 (a) and (b), there were two connection testing configurations

used, one with single bolt and other with two bolts. The length of all the connection test

specimen was determined to be 28 inches for 3:1 span: depth ratio including 3 inches bearing

length on each side.

The steel side plate is shown in the Figure 3-3. Both the ends of the plate were tapped

with threaded holes for facilitating its connection to the top bearing plate. Steel side plates (#3 in

Figure 3-2) were made from 1/2” thick A36 steel, with a length of 7 inches and width of 3

inches. Oversized holes of 1/2 inch and 5/8 inch were drilled for 3/8 inch and ½ inch bolt size

respectively. Four holes were drilled in each plate with a hole located at a distance of 1 inch from

the end and the distance between the two adjacent holes was three times the diameter of the bolt

used, (1.125 inch and 1.5 inch for 3/8 inch and ½ inch holes, respectively). Different size holes

drilled on each ends optimized the usage of steel plates by not having to make different set for

different diameter bolts.

Figure 3-3: Connection Fixtures Steel Side Plate

The connection fixtures top bearing plate (#4 in Figure 3-2) is shown in figure 3-4 and

was manufactured from 1 inch thick A36 steel, with length and width of 6 inches and 3 inches,

respectively. The top bearing plate was slotted along its length for screws to be inserted flush

with the bearing surface of the plate. This provided a rigid connection to the steel side plates.

30

The screws were then threaded into the tapped holes of the steel side plates. Such connection

detailing reduced the chance of a gap in the connection by allowing the steel side plates to snugly

fit the different thicknesses of main member used. Washers and ½ inch and 3/8 inch nuts for

respective bolts were then turned finger tight on the bolt(s) placed through the predrilled main

member and side plates for setting up the connection fixture (Finkenbinder 2007).

(a) (b)

Figure 3-4: Connection Fixture – (a) Side View, (b) Top View

3.5.1.2 Connection Test Protocol

The testing apparatus used a 20,000 pounds capacity load cell attached to the load head of

a 55,000 pounds capacity MTS universal testing machine. A series of linear variable differential

transformers (LVDT’s) and string potentiometers were used to measure deflection. The

LabVIEWTM

7 Express data acquisition software was used to process the electronic

measurements from all sensors.

To remove slack from the system, the connection test specimen was loaded to 100 lbs.

prior to the actual connection test loading to seat the bolt in the connection and the specimen at

the supports. The connection test loading was then initiated after the removal of this load. The

displacement controlled load was applied at a constant rate of 0.025 inch/min, untill the capacity

31

was reached. Capacity was considered to be achieved when the load level dropped by 10% of the

maximum value, without any indication of a recovery.

The LVDT measurement arrangement was similar to that used by Finkenbinder (2007)

who adopted the arrangement of Reshke (1999). Instead of the ASTM D 5652 LVDT

arrangement, this arrangement was adopted for displacement measurement that took into account

the joint slip measurement as two separate components, the splitting of wood and the bearing

failure of wood. Figure 3-5 shows the measurement arrangement that includes six LVDT’s and

string potentiometers on the test specimen. LVDT’s were numbered as LVDT-1 through LVDT-

6 to avoid confusion. The description of these LVDT’s can be seen in Table 3-2. (Finkenbinder

2007).

Table 3-2: Description of locations where LVDT’s measured displacement

LVDT Number Description and Location

LVDT-1 Displacement at left support

LVDT-2 Displacement at right support

LVDT-3 Fixture displacement- located on back side plate

LVDT-4 Fixture displacement- located on front side plate

LVDT-5 Displacement at the top edge

LVDT-6 Displacement at the bottom edge

Figure 3-5: LVDT set-up figure

32

Detailed descriptions with figures of the LVDT-1 through LVDT-6 are shown below.

LVDT-1 and LVDT-2 have a 2 inch range and 0.001 inch sensitivity and measured the

displacement at supports of the main member of the connection with respect to the base of the

testing machine. The mounting of the LVDT to the testing machine and the manner in which

LVDT cores were hung from brackets mounted on the connection test member can be seen in

Figure 3-6.

Figure 3-6 LVDT 1 and 2 Installation Detail

LVDT-3 and LVDT-4 were string potentiometers having a 5 inch range and 0.012 inch

sensitivity. These measured the displacement of the connection fixture with respect to the MTS

load head. “These were mounted on the base of the testing machine on both sides of the fixture,

and connected to the side plates of the fixture with a rod threaded into the fixture itself. The

rod/fixture connection was tightened with the use of a nut, in order to prevent movement of the

rod during testing” (Finkenbinder 2007). Figure 3-7 shows the placement of LVDT-3 and

LVDT-4.

33

Figure 3-7: LVDT 3 AND 4 Installation Detail

LVDT-5 has a 2 inch range and 0.001 inch sensitivity and measured the displacement of

the top edge of the connection test specimen. Figure 3-8 shows the mounting of LVDT-5 with

the help of a fixture that extended above the test specimen from the base of the testing machine

and touched a “Z” shaped bracket glued to the center of the connection test specimen

(Finkenbinder 2007).

Figure 3-8: LVDT 5 Installation Detail

34

LVDT-6 has a 1.5 inch range and 0.001 inch sensitivity and measured the displacement

of the bottom edge of the connection test specimen. Figure 3-9 shows the mounting of LVDT

from the base of the testing machine and the suspension of LVDT core from a bracket mounted

on the bottom edge of the connection test specimen. “The bracket was attached with a quick

setting epoxy, as a screw would have significantly reduced the member cross section at this

critical location” (Finkenbinder 2007).

Figure 3-9: LVDT 6 Installation Detail

With reference to the LVDT’s configuration explained in the above paragraphs, the joint

performance was calculated as per the following mathematical expressions from (Reshke 1999):

Fixture displacement = (LVDT 3 + LVDT 4) / 2 (Eqn 3-1)

Represented the average of the two displacement readings taken from the side plates of the

connection fixture.

Support displacement = (LVDT 1 + LVDT 2) / 2 (Eqn 3-2)

Represented the bearing displacement at the supports of the connection specimen.

Joint cracking = LVDT 6 – LVDT 5 (Eqn 3-3)

Measured the amount of splitting present in the main member of the connection by

computing the difference between the displacements of the bottom and top edge of the

connection test specimen.

35

Joint bearing = Fixture displacement – LVDT 6 (Eqn 3-4)

Measured the amount of deformation due to the dowel bearing on the main member by the

difference between the fixture displacement and the bottom edge of the connection specimen.

Joint slip = Joint cracking + Joint bearing (Eqn 3-5)

Represented the sum of the joint cracking and joint bearing components.

Flexural displacement = LVDT 6 – Support displacement (Eqn 3-6)

Represented the deformation of the bottom edge of the connection specimen without the

effect of support displacement.

For each test performed, a plot of load vs. joint slip was obtained with the help of these

parameters. Also, analysis was carried out to determine the 5% offset yield load and the ultimate

load, and their corresponding displacements.

Other observations included the recording and observation of the mode of failure and

lengths of noticeable cracks by visual inspection. Also the area near and around the bolt hole in

the main member was preserved for future analysis, if needed be, by cutting center of the

connection to obtain a 6 inch long, full depth and full thickness block (Finkenbinder 2007).

3.5.2 Material Testing

The material testing included the dowel bearing strength and dowel bending strength tests

to predict connection behavior from TR-12 (AF&PA 1999), modulus of elasticity (E), shear

modulus (G), Mode I fracture energy and tension perpendicular to the grain strength to predict

connection behavior from Van der Put and Jensen models. The moisture content and specific

gravity testing of the specimens were also included.

The testing procedures followed the pattern as shown previously in Figure 3-1, where the

E and G testing were performed on 86 inches long specimens before cutting them down to 28

inches long specimen for connection testing. This was due to minimum span requirement of 8

times the depth for E and G testing. The specimens for the dowel bearing, tension perpendicular

to the grain, Mode-I fracture energy, moisture content and specific gravity, and the 6 inches long,

full depth and full thickness center block were taken from above or below the splitting

occurrence. A typical example of the cutting locations of these test specimens is shown in the

Figure 3-10.

36

Figure 3-10: Figure of the sample locations taken from the connection test specimen

Here, A- Center Block, B- Dowel Embedment Specimen, C- Tension Perpendicular to Grain

Specimen, D- Mode I Fracture Specimen, and E- Moisture Content and Specific Gravity

Specimen.

3.5.2.1 Test Method for Shear Modulus

The torsion test outlined by ASTM D 198-05, Standard Test Methods of Static Tests of

Lumber in Structural Sizes (ASTM 2005b) was refered to obtain the shear modulus. Previous

research from Harrison (2006) and Finkenbinder (2007) provides a proof of this modified

method being a suitable method for the calculation of shear modulus for wooden composites.

The specimen was fixed at one end and a torque was applied at the other end. The angular

deflection was measured with help of clinometers that were connected at symmetric points along

the length of the specimen.

A sample size of 12 was decided with 85% confidence, calculated from Equation 3-1

with a maximum COV of 10.8% obtained by Finkenbinder (2007) from similar experiment on

LVL. As the length of the specimen should be a minimum of eight times the largest cross

sectional dimension, the tests were conducted before the specimens were cut to the decided

span:depth ratio of 3:1. These specimens were also used for the modulus of elasticity testing.

The test setup consisted of a MTS universal testing machine torsion actuator with a

capacity of 50,000 inch-lb., with a 500 inch-lb. sensitivity and a fixed grip at the other end as

shown in Figure 3-11. Both, the actuator and the end grip were bolted to the laboratory floor to

provide a rigid connection. All specimens were tested at a gage length defined as the distance

between the two clinometers.

37

Figure 3-11: ASTM D 198 Torsion Test Setup

Two Accustar® II/DAS 20 Dual Axis Clinometers (20 degrees rotation range, 0.01

degrees sensitivity) were used to measure the angular deflection. These clinometers were placed

at 16 inches from each end according to the ASTM D 198 provisions (ASTM 2005b). The gage

length between these two clinometers was 32 inches. LabVIEWTM

7 Express data acquisition

software helped in the collection of the electronic measurements recorded by the torsion and

rotation.

A torsional loading rate of 0.5 degrees per minute up to an angular deflection limit of two

degrees was used in accordance to Finkenbinder (2007), to ensure the loading is in the elastic

range and to prevent permanent deformation.

The shear modulus was calculated from the average slope of the torque-angular

displacement curve obtained from the data after three repetitions for each specimen. The

following equation from ASTM D 198-05 was used for the purpose of shear modulus

calculations:

( ) ϑλ

T

h

bhb

LG

−

=

3

16

16

3

(Eqn 3-7)

Where,

G = shear modulus (psi.)

38

L = member gage length (inch), (distance between clinometers)

b = thickness of member (inch)

h = height of member (inch)

λ = St. Venant constant

T/θ = slope from torque-angle curve (lb-inch/radian)

θ = θ1-θ2 = change in angle between clinometers (radian)

T = torque at proportional limit

3.5.2.2 Test Method for Modulus of Elasticity (MOE)

The flexure test outlined by ASTM D 198-05, Standard Test Methods of Static Tests of

Lumber in Structural Sizes (ASTM 2005b) was followed for the measurement of the E. Simply

supported specimens were loaded at mid span and the deflection was measured at mid span using

an LVDT. The same specimens from the shear modulus test were used for the MOE testing. A

sample size of 12 was decided with 85% confidence, calculated from Equation 3-1 with a COV

of 9.2% obtained by Finkenbinder (2007) from similar experiment on LVL.

The testing setup consisted of a MTS universal testing machine of 55,000 lbs. capacity,

fitted with a load cell of 5,000 lbs attached to the load head. A yoke with an LVDT was used to

measure the deflection at center of the specimen. The data from MTS actuator and LVDT was

collected and processed in the LabVIEWTM

7 Express data acquisition software. The set up is

shown in Figure 3-12.

Figure 3-12: Three-Point Bending Test Configuration

39

The clear span between the supports was 80 inches which was in accordance with the

ASTM D 198-05 requirements for “beams intended primarily for evaluation of flexural

properties” that specifies that the span: depth ratio has to be between 5:1 and 12:1 (ASTM

2005b). ASTM D 198-05 loading conditions were not followed for the purpose of this testing. In

accordance with Finkenbinder (2007), the specimens were loaded to 1500 lbs at the rate of 0.20

inch/min to obtain a load deflection curve for MOE calculation but prevent permanent damage.

Similar to the shear modulus testing, MOE testing used three repetitions per specimen

and the average apparent modulus of elasticity was calculated from the following equation:

∆=

I

LPE f

48

3

(Eqn 3-8)

Where,

Ef = apparent modulus of elasticity (psi)

L = span (inch)

I = moment of inertia (inch4)

P/∆ = slope of load-deflection data (lb/inch)

Apparent modulus of elasticity is composed of both bending and shear deflection

components. To obtain the true modulus of elasticity the following equation is given by ASTM

D 198-05:

+

=

2

2111

L

h

KGEE f

(Eqn 3-9.1)

Where,

Ef = apparent material modulus of elasticity (psi)

E = true material modulus of elasticity (psi)

K = shape factor (5/6 for rectangular beams) (Equation X4.2 ASTM D 198-05)

G = shear modulus (psi)

h = height of beam (inch)

L = length of beam (inch)

40

The average shear modulus values from the torsion test method described in section

3.5.2.1 was used in the Equation 3-9.2 to calculate average true modulus of elasticity.

−=

2

2111

L

h

KGEE f

(Eqn 3-9.2)

Where,

Ef = average apparent material modulus of elasticity (psi)

E = average true material modulus of elasticity (psi)


G = average shear modulus (psi)

h = height of beam (inch)

L = length of beam (inch)

3.5.2.3 Test Method for Dowel Bearing Strength

The procedure of ASTM D 5764-97a, Standard Test Method for Evaluating Dowel-

Bearing Strength of Wood and Wood-Based Products (ASTM 2005j) was referred to obtain the

dowel bearing strength. Specimens were cut close to center block as shown in Figure 3-10 with

no damage due to splitting or crushing. The specimen sizes for LVL-1 were 2.5 inches wide,

1.75 inches thick and 4 inches long and LVL-2 were 2.5 inches wide, 1.5 inches thick and 4

inches long. These specimen dimensions were in accordance with the section 8.2 of ASTM D

5764-97a (ASTM 2005j).

Each specimen was predrilled with either a 9/16 inch or a 7/16 inch diameter hole in the

center of the wide face to provide over sizing of 1/16 inch for ½ inch and 3/8 inch bolts,

respectively. This also matched the hole over sizing used for the connection testing. The Figure

3-13 shows a sample specimen used for dowel embedment test.

41

(a) (b)

Figure 3-13: ASTM D 5764-97a, (a) Full Hole Dowel Embedment Strength Specimen, (b)

Dowel Embedment Test Set-Up

Samples for the dowel bearing strength test were cut from all 130 connection test

specimens. The specimens were placed in a test setup as shown in the Figure 3-14 which had a

bolt through the specimen and rigid steel side plates. One-half inch and 3/8 inch diameter bolts

of SAE J429 Grade 8 bolt were used to ensure wood specimen failure without causing the bolt to

bend were used.

A compression load was applied at the end of the specimen with an MTS universal testing

machine using a 10,000 lbs load cell and a floating load head to adjust for any eccentricities on

face of the specimen. A loading rate of 0.15 inch/min was used to ensure failure occurred

between 1-10 minutes as mentioned in the section 10.4 of ASTM D 5764-97a (ASTM 2005j).

The testing was stopped when the dowel was embedded fully into the material or when the

maximum load was reached. Decision of the deflection limit of dowel bearing strength was

previously found to have a direct effect on TR-12 model predictions (Finkenbinder 2007).

The results were interpreted as per the Section 11 of ASTM D 5764-97a (ASTM 2005j).

Dowel bearing strength values at both 5% offset yield and at capacity were determined by

dividing the resistance load by bolt diameter and embedment specimen bearing length.

42

3.5.2.4 Test Method for Bolt Bending Strength Test

The procedure of ASTM F 1575-03, Standard Test Method for Determining Bending Yield

Moment of Nails was considered for determining the bolt bending strength (ASTM 2005d).

According to NDS section 11.3.5, dowel bending strengths “shall be based on yield strength

derived using methods provided in ASTM F 1575 or the tensile yield strength derived using

procedures of ASTM F 606” (AF&PA 2005).

According to ASTM F 1575, the fastener was loaded in a three-point bending

configuration, where the span length was defined as a function of diameter of the fastener. The

required span length of ½ inch and 3/8 inch diameter bolt was found to be 5.75 inches and

4.3125 inches, respectively (ASTM 2055d). These span lengths were larger than span of the bolt

being used in this research and so a different testing procedure was implemented (Finkenbinder

2007).

In conjunction to Billings (2004), Albright (2006), and Finkenbinder (2007), the

cantilever bending test method was deemed suitable for this purpose. The set up consisted of a

cantilever bolt threaded into a rigid support fixture, with an application of a concentrated load (P)

at a distance (X) from the face of the support fixture as shown in Figure 3-15.

(a) (b)

Figure 3-14: (a) Diagram of Cantilever Bending Test Method, (b) Bolt Bending Test Set-Up

43

A sample size of 15 was decided with more than 90% confidence considering COV of

10%. The distance (X) was taken as 2.5 inch for 3/8 inch and 2.0 inch for ½ inch specimens. A

10,000 lbs load cell was used for applying a load rate of 0.1 inch/minute with a MTS universal

testing machine. A cylindrical load point of 0.375 inch diameter was used by the load head. This

set up configuration can be referred from Figure 3-16.

The 5% offset yield and capacity resistance values were calculated from the recorded

load displacement data of each specimen. As per the Section 10.1 of ASTM F 1575, 5% offset

yield was determined by “fitting a straight line to the initial portion of the load-deformation

curve, offsetting this line by a deformation equal to 5% of fastener diameter, and selecting the

load at which the offset line intersects the load deformation curve. In those cases where the offset

line does not intersect the load deformation curve, the maximum load shall be used as the yield

load” (ASTM 2005d). The maximum resistance obtained from load displacement data of

specimen was considered to be the capacity resistance and the bending yield strength, Fyb, was

calculated with the help of following equation:

=

Z

MFyb

(Eqn 3-10)

Where,

Z = fastener plastic section modulus = D3/6 (in

3)

D = fastener diameter (inch)

M = applied moment = P*X (lb-inch)

P = 5% offset yield load (lbs.)

X = distance from face of support to the location of load application (inch)

For calculations of the yield model, average bending yield strength values from 5% offset

yield, of these 15 specimens, for each diameter bolts, was used.

3.5.2.5 Test Method for Tension Perpendicular to Grain

The procedure of ASTM D 143-94, Standard Test Methods for Small Clear Specimens of

Timber (ASTM 2005a), was followed for determining tension perpendicular to grain strength.

Specimens were cut as shown in Figure 3-10, from a part of the cross section undamaged by

splitting or crushing.

44

Specimen size used for testing was 2-1/2 inch x 2 inch x 1-3/4 inch for LVL-1 and 2-1/2

inch x 2 inch x 1-1/2 inch for LVL-2, based on recommended options from ASTM D 143-94,

which is 2-1/2 inch x 2 inch x 2 inch. The difference was due to the width of material used for

this research.

One specimen was cut from each of the 130 connection test specimens. Speed of testing

was 0.10 inch/minute as mentioned in ASTM D 143-94, until ultimate load was reached (ASTM

2005a). Specimens were placed in a test setup as shown in Figure 3-15.

Figure 3-15: ASTM D 143 Tension Perpendicular to Grain Specimen and Test Set-Up

Sketches of the failed specimen were recorded on the data sheet. Load-displacement

curve data was recorded from the test results and the ultimate tension perpendicular to grain

stress was determined from the analysis of this curve, pertaining to the following equation.

ft = Pmax/A (Eqn 3-11)

Where,

ft = tension perpendicular to grain strength (psi)

Pmax = maximum load from load-displacement curve (lbs)

A = failure cross sectional area of specimen (in2)

45

3.5.2.6 Test Method for Mode-I Fracture

There were no specific standards available for testing fracture properties of wood

composites when this research was performed. However several assumptions and methods

successfully implemented by previous researchers for similar cases have been used. The ASTM

D 5045-99, Standard Test Methods for Plane-Strain Fracture Toughness and Strain Energy

Release Rate of Plastic Materials (ASTM 2005h) and ASTM E 399-90, Standard Test Method

for Plane-Strain Fracture Toughness of Metallic Materials (ASTM 2005c), were considered.

These methods were not followed exclusively as they are for metal and plastic materials which

are isotropic and homogeneous whereas as LVL is not (Ramskill 2002 and Finkenbinder 2007).

Considerations for this experiment from Ramskill (2002) and Finkenbinder (2007) are as

follows:

o A very sharp crack tip was ensured to obtain least possible value for fracture toughness as

a cracked tip that is not sharp would increase the radius of curvature and thereby decrease

the stress intensity around the tip.

o The specimen was wide enough to ensure a plane strain condition and was held by a

clevis, loaded in tension by pins that allowed rotation of the specimen during testing.

o To maintain the criteria of linearity, the ligament length (W-a) was long enough to avoid

excessive plasticity that is to ensure that the plastic zone is concentrated to a very small

area at the crack tip.

o A constant loading rate was used such that it allowed minimum fast crack propagation to

obtain a smooth load vs. displacement curve.

o Indentation tests on un-cracked specimens were performed as per Section 9.2 of ASTM D

5045-99 (ASTM 2005h), with the loading pins. This was to obtain a corrected load vs.

displacement curve after considering the embedment effect caused by the loading pins.

Fracture test specimens were cut from all 130 connection test specimens from the

location shown in Figure 3-10. Dimensions of the compact tension (CT) test specimen used for

this research were similar to as used by Ramskill (2002) and Finkenbinder (2007) and are shown

below in the Figure 3-16.

46

Figure 3-16 Fracture Specimen Dimension

Where,

L = total length = 5.78 inches

a = crack length from end of the crack to center of dowel = 1.75 inch

W = length of specimen from center of dowel to un-cracked end = 5.39 inch

B = width of the specimen = 1.75 inch (LVL-1) and 1.5 inch (LVL-2)

h = height of the specimen= 1.5 inch

c = center to center distance between dowels = 0.65 inch

b = thickness of the crack = 0.12 inch

d = length of specimen from center of dowel to cracked end = 0.39 inch

Φ = diameter of the holes drilled in the specimen for inserting pins = 0.255 inch

An MTS universal testing machine with a load cell of 10000 lbs capacity was used for

testing. Internal transducers of the machine were used for recording the displacement. The

loading pins which ran through the holes were of 0.25 inch diameter. Figure 3-17 shows the

picture of this set up (Finkenbinder 2007).

47

Figure 3-17: Fracture Test Fixture Set-Up

Rate of loading of 0.075 inch/min was used to allow the specimen to fracture in 6-9

minutes range. The tests were ended when the load reduced to 95% of the maximum load. The

Mode I fracture energy was then obtained from the following equation:

A

WG If = (Eqn 3-12)

Where,

GIf = Mode I Fracture energy (lb-in/in2)

W = area under the load v/s displacement curve (lb-in)

A = area of total crack propagation (in2)

The area (A) is determined by multiplying the average length of the crack with the thickness (B).

The average length of the crack is obtained by measuring the horizontal projection made by it.

3.5.2.7 Test Method for Moisture Content and Specific Gravity

Immediately after the connection specimens were tested, samples for moisture content

and specific gravity measurement were taken. The location of sample was shown in Figure 3-10.

The moisture content and specific gravity measurement was done as per ASTM D 4442-92,

Method A (ASTM 2005g) and ASTM D 2395-93, Method B, Mode II (ASTM 2005e)

respectively. The samples were oven dried for a week after measuring its initial weight. Then the

oven dried weight was measured and the moisture content value was calculated according to the

following equation.

48

�� 100% (Eqn 3-13)

Where,

MC= moisture content (%)

Wo= initial weight of sample (grams)

Wd= dried weight of sample (grams)

The same oven dried specimens were then used to obtain specific gravity. Specimens

were dipped into paraffin wax to seal the surface and prevent water from entering the sample.

These specimens were suspended in a tank of water and the increase in mass displacement was

measured. The volume of specimen was obtained by dividing the increase in weight observed, by

specific gravity of water that is 1 when weight is in grams (Billings 2004). With these parameters

the specific gravity was calculated by the following equation.

�� (Eqn 3-14)

Where,

SG= specific gravity

MC= mass of the dry section

Vol= volume of specimen

3.6 Definitions for Test properties

The properties and geometries of the material and connections obtained experimentally,

as discussed in previous sections, were used as an input data for TR-12, Vander Put, and Jensen

model equations. The 5% offset yield resistance, capacity resistance, elastic stiffness, and

ductility ratio values were calculated from the connection test data obtained from connection

tests. To help in understanding these values, a load-slip curve is shown in the Figure 3-20.

49

Figure 3-18: Load-Slip Curve, with calculated values

These values have been described below in brief:

o 5% offset yield resistance and slip: was defined as a point of intersection of the load-slip

curve and offset line. 5% offset yield point was considered to be equal to the capacity point in

cases where the intersection point was located at a point beyond capacity.

o Capacity: was defined as the maximum resistance recorded by the load-slip curve.

o Elastic stiffness: was defined by the slope of the initial linear portion of the load-slip curve.

This same line is moved to its right to a distance equal to 5% of the dowel diameter for

determining the 5% offset yield.

o Ductility ratio: was calculated as the slip at capacity divided by the slip at 5% offset yield, for

our research purpose, similar to as calculated by Finkenbinder (2007). This definition of

ductility ratio differed from as defined by some researchers in parallel to grain connection,

where it was defined as the slip at failure divided by the slip at 5% offset yield. This change

was made due to catastrophic failure of SCL specimens observed at failure (Finkenbinder

2007).

A procedure from Smart (2002), was used to obtain average load-slip curves for each

connection configuration set. In this procedure, each curve from a set was plotted to the point

where slip values were recorded. This information was then used to plot an average load slip

curve for that set.

5% Offset Yield Failure

Elastic Stiffness

Capacity

0.05

50

CHAPTER 4: RESULTS AND DISCUSSION: Comparison of Single and Two Bolted LVL

Perpendicular to Grain Connections: TR-12 Model

This chapter includes the objective of measuring properties from single and two bolted

connections loaded perpendicular to grain in double shear for LVL from two different

manufacturers and comparing the connection test resistance to yield based model and design

literature including the TR-12 and NDS ASD. The chapter is written in a form of a paper to be

submitted to the ASCE Journal of Materials in Civil Engineering.

4.1 Abstract

Perpendicular to grain connections in wood are found in practical applications such as beam to

column connections. Little research is available for perpendicular to grain connections in wood,

particularly for structural composite lumber. This paper compares experimental testing of single

and two bolted connections to predicted values generated by the American Wood Council’s

Technical Report 12 methods. Two different laminated veneer lumber materials were tested with

variable loaded edge distances, bolt sizes, and single and two bolted connections. Connection

testing showed splitting failures combined with crushing of main member material and formation

of a single plastic moment. Connection resistance increased with increased loaded edge distance

and number of bolts. The allowable shear design value controlled the National Design

Specification (NDS) Allowable Stress Design (ASD) lateral design value in general to the

connection design except for one case with 7D loaded edge distances for two bolts of 12.7 mm

(0.5 inch) where connection design strength values controlled. The allowable shear check value

for single bolt at 4D loaded edge distances was over 500% lower than the allowable connection

strength values. The 5% TR-12 values controlled over allowable shear check values for only one

set of 7D loaded edge with two bolt connections. The ratio of test to NDS ASD lateral design

values (T/DC) provided design safety factor (DSF) values, which were observed to be greater at

4D loaded edge distance with single bolt compared to other configurations. Capacity values were

best predicted for the 7D loaded edge distance with single bolt configurations and over predicted

for all other configurations. The model showed a decrease in calculated to test (C/T) ratios with

an increase in loaded edge distance.

51

4.2 Introduction

By weight, wood materials are used more than plastics, metals and cement combined (Eco-link

2001). Wood composites are a form of structural wood material and a detailed understanding of

material properties and behavior of structural composite lumber (SCL) products is necessary for

continued usage (Hindman et. al 2009). Particularly, connections are one of the weakest links in

wood construction and are considered to be a critical part of structural design.

The National Design Specification for Wood Construction, commonly abbreviated as the NDS,

(AF&PA 2005) outlines procedures for designing wood structures in the United States. The

NDS connection design relies upon a series of general dowel equations based on yield theory

given by Johansen (1949). Yield theory assumes that the connection exhibits a ductile behavior

until the capacity resistance is reached. Splitting or cracking of the wood member is accounted

for by two provisions; fastener spacing requirements and an additional check of member shear

stress (AF&PA 2005).

Finkenbinder (2007) studied the behavior and properties for single bolt connections in

machine stress rated (MSR) lumber, laminated veneer lumber (LVL) and parallel strand lumber

(PSL) with variable loaded edge distance and span: depth ratios. Finkenbinder (2007) observed

brittle failure characterized by splitting for specimens loaded at lower edge distances and a

mixed failure characterized by splitting and crushing or bending for specimens loaded at greater

edge distance, for all three materials. In most of the cases, TR-12 was found to be more accurate

than the fracture models and all the three models over predicted the connection capacity at low

loaded edge distance. Results from Finkenbinder (2007) showed that the calculated to test (C/T)

ratio with different loaded edge distances, were found to be more stable and consistent for Van

der Put model than the other models. For all three materials and the variable span: depth ratio

had a negligible effect on both connection and model performance.

Multiple bolted connections are the most commonly used type of connection in the field today,

yet little research data is available on laterally loaded multiple bolt connections perpendicular to

the grain than that available for single bolted connection. As mentioned by Smith and Foliente

(2002), research related to bolted connections, particularly with multiple bolts loaded in

perpendicular to the grain direction, is of high priority.

52

4.3 Literature Review

The NDS currently uses both the allowable stress design (ASD) and load resistance factor design

(LRFD) design methodologies for computation of design stresses. Both methods depend on the

European Yield Model (EYM) and design provisions for mechanical connections and dowel type

fasteners are discussed in Chapters 10 and 11of the NDS (AF & PA 2005).

The adjusted reference lateral design value (Z’) is used for comparison to the imposed

connection loads. The Z’ value is obtained by multiplying the reference lateral design value (Z)

with the applicable adjustment factors explained in Table 10.3.1 of the NDS (AF&PA 2005).

The Z value is the minimum load value obtained from the applicable yield limit equations for

different yield modes in Table 11.3.1A of the NDS (AF&PA 2005).

Z’ = Z(CD)(CM)(Ct)(Cg)(C∆)(Ceg)(Cdi)(Ctn) (Eqn: 4-1)

Where,



CD = load duration factor CM = wet service factor Ct = temperature factor

Cg = group action factor C∆ = geometry factor Ceg = end grain factor

Cdi = diaphragm factor Ctn = toe-nail factor

There are four yield conditions for double shear loading, Mode Im, Mode Is, Mode IIIs and Mode

IV. Mode Im and Is represent bearing-dominated yielding of wood fibers in contact with the

fastener in either the main or the side member(s), respectively. Mode IIIs failure represents

fastener yield in bending at one plastic hinge point per shear plane, and bearing dominated yield

of wood fibers in contact with the fastener in the side member(s). Mode IV failure represents

fastener yield in bending at two plastic hinge points per shear plane, with limited localized

crushing of wood fibers near the shear plane (AF&PA 2005). The yield limit equations for the

two shear as mentioned in the NDS Table 11.3.1A are as follows:

53

MODE Im: d

emm

R

FDlZ = (Eqn: 4-2)

MODE Is: d

ess

R

FDlZ

2= (Eqn: 4-3)

MODE IIIs: de

ems

RR

FDlkZ

)2(

2 3

+= (Eqn: 4-4)

MODE IV: )1(3

22 2

e

ybem

d R

FF

R

DZ

+= (Eqn: 4-5)

Where,

2

2

33

)2(2)1(21

sem

eyb

e

e

lF

DRF

R

Rk

++

++−=

D = dowel diameter, (inch)

Fyb = dowel bending yield strength, (psi)

Rd = reduction term, (Table 11.3.1B, NDS AF&PA 2005)

Re = Fem/Fes





The above mentioned equations are based on the assumptions that there is no gap and no friction

between the faces of the connected members, the load acts perpendicular to the axis of dowel,

and edge distances, end distances, spacing and penetration are in accordance with Section 11.1.2

of the NDS (AF & PA 2005).

General Dowel Equations for Calculating Lateral Connection Values - Technical Report 12

(AF&PA 1999), which is commonly referred to as TR-12, is an expanded form of NDS general

dowel equations (AF&PA 2005). Equations from TR-12 predict connection loads at the

proportional limit, 5% offset yield load and at capacity for all yield modes. The equations

presented in TR-12 also allow for inter member gaps and fastener moment resistance. TR-12

54

does not consider the end fixity (resistance to rotation provided at the ends of the dowel) and

effect of friction between the connection members. In order to obtain the factored allowable

design load based on the 5% offset, the critical governing load P, the minimum load determined

from the equations, is divided by the applicable reduction terms as provided in Table 2 of TR-12

(now equivalent to the Z term from the NDS). The Z values are multiplied by the adjustment

factors including load duration, wet service, temperature, size, flat use, incising, stability,

repetitive member, curvature, shear stress, buckling stiffness and bearing area, as mentioned in

the NDS to develop the Z’ value (Ramskill 2002 and Finkenbinder 2007).

When load is applied perpendicular to grain to a wood member with a reduced cross-section

(such as bolt hole), an additional shear stress check must be performed as defined by NDS

Section 10.1.2 (AF&PA 2005). For perpendicularly loaded beam connections, the adjusted shear

design check as mentioned in the Section 3.4.3 of the NDS is necessary. When the connection is

located at a distance less than five times the depth of the member, from the end of the member,

Equation 4-6 is used to calculate the adjusted design shear value. For a connection located at a

distance greater than five times the depth of the member from the end of the member, the

Equation 4-7 is used to find out adjusted design shear value (AF&PA 2005).

2

3

2

′=

′

d

dbdFV e

evr (Eqn: 4-6)

′=

′evr bdFV

3

2 (Eqn: 4-7)

Where,

Vr' = adjusted design shear, (lbs.) Fv' = adjusted shear design value parallel to grain, (psi.)

b = width of member, (inch) d = depth of member, (inch)

de = depth of the member, less the distance from the unloaded edge of the member to the center

of the nearest bolt, (inch)

The adjusted design shear parallel to the grain value (Fv’) is determined by multiplying the

tabulated shear parallel to the grain value (Fv) to the applicable adjustment factors obtained from

Table 4.3.1 of the NDS. Equations 4-8 and 4-9 calculate the adjusted design shear parallel to the

grain values for ASD and LRFD (AF & PA 2005):

55

For ASD Fv’ = Fv (CD)(CM)(Ct)(Ci) (Eqn: 4-8)

For LRFD Fv’ = Fv (KF)(φv)(λ)(CM)(Ct)(Ci) (Eqn: 4-9)

Where,

Fv’ = adjusted design shear parallel to grain value, (psi.)

Fv = tabulated shear parallel to grain value of the member, (psi.)


CD, CM, and Ct as explained in equation 1 Ci = incising factor

φv = shear resistance factor = 0.75 KF = format conversion factor = 2.16/ φv = 2.88

Multiple bolted connections are the most commonly used connections, yet little research data is

available on laterally loaded multiple bolt connections perpendicular to the grain. The design

method for multiple fastener connections uses the group action factor (Cg), in modifying the

adjusted reference lateral design value (Z’) per connection. The strength of a multiple bolted

connection is calculated by summing the single fastener strength values after multiplying by a

modifying factor Cg. The strength of the multiple fasteners connection depends on the number of

fasteners in a row, the spacing of fasteners, the load slip modulus for the connection, the

modulus of elasticity and gross cross sectional area of main and side members, and whether the

rows are in a symmetric or staggered pattern. The Cg factor was formulated by Zahn (1991) and

Section 10.3.6 of the NDS (AF&PA 2005), specifies an equation for calculating it.

Finkenbinder (2007) considered a beam monotonically loaded perpendicular to grain at mid-span

with a single bolt laterally loaded in double-shear. Finkenbinder (2007) compared the

experimental test results with theoretical predictions from three models: the TR-12, Van der Put

and Leijten (2000), and Jensen et al. (2003). A hundred and twenty double shear connection tests

and 550 material property tests for property input values for the three models were performed

and variables considered for the research were variable span:depth ratio (3:1, 5:1, 10:1), variable

loaded-edge distances (4D, 7D, 10D where D is the dowel diameter), and different main member

material (southern pine (MSR) lumber, (LVL) and (PSL)). Brittle failure characterized by

splitting for specimens loaded at lower edge distance and a mixed failure characterized by

splitting and crushing or bending for specimens loaded at greater edge distances was observed

for all three materials. In most of the cases, the TR-12 model was found to be more accurate than

56

the fracture models. All three models over predicted the connection capacity at low loaded edge

distance. Finkenbinder (2007) also showed that the C/T (calculated to tested value) results over

the range of loaded edge distances for Van der Put model results were more stable and consistent

than the other models. For all three materials, the variable span: depth ratio had a negligible

effect on both connection and model performance.

This paper compares the predictions from TR-12 equations to connection test results for both

single and two bolted connections loaded perpendicular to grain. LVL from two different

manufacturers was used. The results obtained from the experimental testing will provide

information regarding the behavior of connections at conditions of capacity and yield, and a

comparison between single and multiple bolted connections for LVL from different

manufacturers and a comparison of the experimental results with the predictions from NDS ASD

design values and TR-12 general dowel equations.

4.4 Materials and Methods

Connection testing of single and two bolted connections loaded perpendicular to grain was

conducted with subsequent dowel bearing strength, bolt bending, moisture content and specific

gravity tests. Dowel bearing strength and bolt bending test values were used as inputs in TR-12

equations.

The materials tested for this research were LVL from two different manufacturers. The first LVL

was from Georgia Pacific known as GP Lam LVL® which was rated as 2.0E and was made from

yellow poplar (Liriodendron tulipifera) and southern pine (Pinus spp.) veneers (ICC-ES 2008b),

and was designated as LVL-1 for this research. The dimensions of LVL-1 were 44.5 mm (1.75

inch) thick by 184 mm (7.25 inch) wide. The second LVL, designated as LVL-2, was from Boise

known as VERSA-LAM® which was rated as 3100f-2.0E and was made from southern pine

(Pinus spp.) and eucalyptus (Eucalyptus spp.) veneers, where the majority of the material was

southern pine (ICC-ES 2008a and Finkenbinder 2007). The dimensions of LVL-2 were 38.1 mm

(1.5 inch) thick by 184 mm (7.25 inch) wide.

Bolts used for testing were of diameters 12.7 mm (0.5 inch) and 9.53 mm (0.38 inch), 108 mm

(4.25 inch) long, low carbon steel, SAE J429 Grade 2 hex head bolts. The minimum tensile yield

57

strength (Fe) for Society of Automotive Engineers (SAE) bolts is listed as 510 N/mm2 (74,000

psi) (Bickford 1998). All bolts were ordered together from the supplier to ensure that bolts of

each size were from the same batch and thereby minimize the chances of variation in the bolts.

4.4.1 Connection testing

Connection testing was carried out as outlined in ASTM D 5652-95, Standard Test Methods for

Bolted Connections in Wood and Wood-Based Products (ASTM 2005a). The connection testing

consisted of displacement controlled monotonic compressive loading of a steel-wood-steel two

shear connection at mid-span of a simply supported beam. Figure 4.1 defines the loaded and

unloaded edge distances, span, overall length, connection layout and detailing.

Figure 4.1: Schematic diagrams for description of the connection detailing, where, 1- Support

Bearing Plates, 2- Bolt, 3- Steel Side Plate, 4- Top Bearing Plate, 5- MTS Load Head, 6- Span,

7- Over All Length, 8- Loaded Edge Distance, 9- Unloaded Edge distance, 10- Load Acting

Point, 11- Depth

The simply supported specimens were loaded at mid-span with steel side members connected to

a top bearing plate, which transmits the load applied by the MTS universal testing machine. The

length of each specimen was 711 mm (28 inch), including a 76.2 mm (3 inch) for bearing area on

either end of the specimen in accordance with 3:1 span to depth ratio. The minimum spacing

between the bolts for multiple bolted connections was three times the diameter of the bolt used

58

(3D) as specified in the NDS (AF&PA 2005). Table 4-1 shows the test plan for the connection

testing and the number of specimens used for each particular set of variables. The variables

included were number of bolts, loaded edge distance and bolt diameter. Total of 130 specimens

were tested with 10 repetitions per group.

Table: 4-1: Test Plan for Connection Testing

SET

Number

of Rows

Number

of Bolts

Loaded Edge

Distance

LVL-1

Bolt

Diameter TOTAL

mm (inch) mm (inch)

L1-1 1 1 4D 50.8 (2.0) 12.7 (0.5) 10

L1-2 38.1 (1.5) 9.53 (0.38) 10

L1-3 7D 88.9 (3.5) 12.7 (0.5) 10

L1-4 66.7 (2.625) 9.53 (0.38) 10

L1-5 1 2 4D 50.8 (2.0) 12.7 (0.5) 10

L1-6 38.1 (1.5) 9.53 (0.38) 10

L1-7 7D 88.9 (3.5) 12.7 (0.5) 10

L1-8 66.7 (2.625) 9.53 (0.38) 10

TOTAL 80

LVL-2

L2-1 1 1 7D 88.9 (3.5) 12.7 (0.5) 10

L2-2 1 2 4D 50.8 (2.0) 12.7 (0.5) 10

L2-3 38.1 (1.5) 9.53 (0.38) 10

L2-4 7D 88.9 (3.5) 12.7 (0.5) 10

L2-5 66.7 (2.625) 9.53 (0.38) 10

TOTAL 50

GRAND

TOTAL 130

The testing apparatus used an 89 KN (20,000 lbs) capacity load cell attached to the load head of

a 245 KN (55,000 lbs) capacity MTS universal testing machine. A series of linear variable

differential transformers (LVDT’s) and string potentiometers were used to measure deflection.

To remove slack from the system, the connection test specimen was loaded to 445 N (100 lbs)

prior to the actual connection test loading to seat the bolt in the connection and the specimen at

the supports. The displacement controlled load was applied at a constant rate of 0.64 mm/min

(0.025 inch/min), until the capacity was reached. Capacity was considered to be achieved when

the load level dropped by 10% of the maximum value, without any indication of a recovery. The

LVDT measurement arrangement was similar to that used by Finkenbinder (2007) who adopted

59

the arrangement of Reshke (1999) which took into account the joint slip measurement as two

separate components, the splitting of wood and the bearing failure of wood.

5% offset yield and capacity values were calculated and obtained from the connection test data

for comparing with the predicted 5% offset yield and capacity values from TR-12 model. 5%

offset yield resistance was defined as a point of intersection of the load-slip curve and offset line

and capacity was defined as the maximum resistance recorded by the load-slip curve

4.4.2 Material testing

Material testing included dowel bearing strength test and bolt bending test for use in TR-12

equations (Equations 4-2 to 4-5). Moisture content (MC) and specific gravity (SG) tests were

also performed. All testing of dowel embedment, MC and SG used a sample from each of the

connection specimens tested. The procedure of ASTM D 5764-97a, Standard Test Method for

Evaluating Dowel-Bearing Strength of Wood and Wood-Based Products (ASTM 2005b) was

referred to obtain the dowel bearing strength. Samples for the dowel bearing strength test were

cut from all 130 connection test specimens as shown in Figure 4.2(a) and were placed in a test

setup as shown in the Figure 4.2 (b) which had a bolt through the specimen and rigid steel side

plates. 12.7 mm (0.5 inch) and 9.53 mm (0.38 inch) diameter bolts of SAE J429 Grade 8 bolt

were used to ensure wood failure without bolt bending.

A compression load was applied to the specimen with an MTS universal testing machine using a

44.5 KN (10,000 lbs) load cell and a floating load head to adjust for any eccentricities on face of

the specimen. A loading rate of 3.81 mm/min (0.15 inch/min) was used that ensured the

occurrence of failure between 1-10 minutes as mentioned in the section 10.4 of ASTM D 5764-

97a (ASTM 2005b). The testing was stopped when the dowel was embedded fully into the

material or when the maximum load was reached. Decision of the deflection limit of dowel

bearing strength has a direct effect on TR-12 model predictions (Finkenbinder 2007).

60

(a) (b)

Figure 4.2: Dowel Bearing Strength: (a) Specimen, (b) Setup

Dowel bearing strength values were calculated for both 5% offset yield and at capacity by

dividing the resistance load by bolt diameter and embedment specimen bearing length and the

values were used as input in TR-12 model equations for 5% offset yield and capacity strength

calculations respectively.

For bolt bending test, a cantilever bending test set up following Billings (2004), Albright (2006),

and Finkenbinder (2007) was used. The exact arrangement details can be seen in Figure 4-3

below. A sample size of 15 was decided with more than 90% confidence considering COV of

10%. The distance (X) was taken as 63.5 mm (2.5 inch) for 9.575 mm (0.375 inch) and 50.8 mm

(2.0 inch) for 12.7 mm (0.5 inch) specimens. A 44.5 KN (10,000 lbs) load cell was used for

applying a load rate of 2.54 mm/min (0.1 inch/min) with a MTS universal testing machine. A

cylindrical load point of 9.525 mm (0.375 inch) diameter was used by the load head.

61

Figure 4-3: Cantilever Bolt Bending set up

4.5 Results and Discussion

4.5.1 Connection Test (CT) Results

According to the NDS, crushing in the wood member (Mode Im) was the expected yield mode

until capacity for the test configurations. During the connection testing, five failures were

observed, splitting (denoted as ‘S’), Mode Im (crushing in the main member), IIIs (single plastic

hinge forming in the main member), and mixed failures of S-Im and S-IIIs. Splitting of the main

member occurred around the middle to lower third of the bolt hole, with no or little crushing

observed near the bolt hole area. Mode “Im” and “IIIs” failure observed were as defined in the

NDS (AF &PA 2005), where “Im” showed bearing failure below the bolt area and “IIIs” showed

formation of single plastic hinge in the bolt with significant crushing below the bolt area. Figure

4.4 shows the failures observed. Note that similar yield mode terms, Im and IIIs as mentioned by

the NDS have been used to specify observed modes at failure for simplicity in tabulating and

writing, so it should not be confused with predicted modes at yield as explained by NDS.

Splitting (S) Mixed Splitting and Crushing (S-Im)

62

Mixed Splitting and Plastic Moment (S-IIIs) Plastic Hinge Formation in Bolt - IIIs

Crushing (Im – Observed at Bottom Bolt Area) Plastic Moment (IIIs – Observed at Bottom

Bolt Area)

Figure 4.4: Failure Types Observed from Connection Testing

Table 4-2 shows the failures observed from testing, with the first failure mentioned being the

more frequently occurring failure. Due the use of steel plates as side members, precise behavior

of the main member at capacity was not observed. The failures (considered at 10% load

reduction from capacity load for our case) were assumed to be the type of failure at capacity.

Modes “Im” and “IIIs” only occurred twice for the two bolt connection (no split at bottom bolt),

for 7D loaded edge distance, for both bolt diameters. The mixed failure of “S-IIIs”, dominated

for all connection tests with the 9.53 mm (0.38 inch) bolt due to lower bolt diameter for these

tests, which would offer lower resistance to formation of a plastic hinge. 12.7 mm (0.5 inch)

diameter bolt provided sufficient resistance to formation of plastic hinge and so, the sets using it

had no Mode IIIs failure observed.

63

Table: 4-2: Failure Modes Observed

Failure Modes

Observed

LVL-1 LVL-2

1-Bolt 2-Bolt 1-Bolt 2-Bolt

Bolt Dia. Loaded Edge Distance Loaded Edge Distance

mm (inch) 4D 7D 4D 7D 7D 4D 7D

12.7 (0.5) S, S-Im S-Im S, S-Im S-Im, Im S-Im, S S S, S-Im

9.525 (0.375) S-IIIs S-IIIs S-IIIs S-IIIs, IIIs S-IIIs S-IIIs

Finkenbinder (2007) obtained three types of failures, S, Im-S and IIIs-S for tests on MSR, LVL

and PSL materials with single bolt of 12.7 mm (0.5 inch) diameter for variable loaded edge

distances and span: depth ratios. The S occured at 4D loaded edge distance in general and mixed

modes Im-S and IIIs-S to occur at 7D and 10D loaded edge distances. In our case, in general

Mode S was observed to dominate for all 4D loaded edge distance, and mixed mode S-Im,

dominated for 7D loaded edge distance for 12.7 mm (0.5 inch) bolts.

Table 4-3 presents connection test results for 5% offset yield and capacity resistance, with

associated coefficient of varaitions (COV). The 5% offset yield and capacity resistance values

were almost 50% greater for the two bolt connection compared to the single bolt for same

material, loaded edge distance, and size of bolts. Two bolt connections were expected to have

greater connection resistance due to increased bearing area due to using two bolts. During the

testing, splitting often occurred at the top bolt, indicating greater load was carried by the top bolt.

Considering this behavior, the two bolt configurations may actually have an additional 3D

distance from the loaded edge.

64

Table: 4-3 Connection Test Results

5% Offset yield, KN

(lbs)

LVL-1 LVL-2


Bolt Dia.

mm

(inch)

Loaded Edge Distance Loaded Edge Distance

4D 7D 4D 7D 7D 4D 7D

12.7 (0.5)

AVG

11.0

(2460)

12.0

(2700)

22.1

(4970)

26.7

(6000)

14.8

(3340)

17.8

(4000)

26.6

(5970)

COV (%) 11.92 14.24 6.22 15.6 9.51 14.72 22.52

9.53

(0.38)

AVG

9.2

(2060)

9.4

(2120)

16.7

(3750)

19.8

(4450)

14.2

(3200)

18.8

(4220)

COV (%) 5.01 8.38 9.13 19.04 12.15 20.1

Capacity, KN (lbs)

LVL-1 LVL-2


Bolt Dia.

mm

(inch)


4D 7D 4D 7D 7D 4D 7D

12.7 (0.5)

AVG

12.0

(2700)

19.9

(4480)

24.1

(5420)

34.9

(7850)

20.5

(4600)

20.8

(4670)

31.8

(7160)

COV (%) 10.39 6.36 6.48 10.64 6.56 5.06 6.63

9.53

(0.38)

AVG

10.6

(2390)

16.4

(3670)

18.2

(4080)

26.8

(6020)

15.8

(3550)

23.6

(5310)

COV (%) 8.5 10.79 6.38 10.21 12.61 5.2

For all directly comparable configurations between LVL-1 and LVL-2, LVL-1 offered greater

resistance than LVL-2. This may be caused by the greater width of the LVL-1 material. COV

and capacity resistance values at 7D loaded edge distances were observed to be greater in

comparison to that at 4D loaded edge distances for similar set of variables, and in particular for

two bolted connections. This was expected due to more material below the bolt available to resist

the load in 7D loaded edge distance case. Finkenbinder (2007) also observed a similar increase in

capacity resistance with increase in loaded edge distance.

4.5.2 Material Test Results

Table 4-4 presents the material property values required for input in the TR-12 model equations.

The dowel embedment strength at 5% and capacity, and the bolt bending strength were the two

major variables required for the TR-12 model equations. Dowel embedment test results showed

that LVL-2 had a greater resistance than LVL-1 for both bolt diameters at 5% offset yield and

capacity. COV ranges for dowel embedment strength test were similar for both materials. For

65

LVL-2 with 12.7 mm (0.5 inch) bolt diameter, the dowel bearing strength were observed to be

greater than observed by Finkenbinder (2007) for the same material and bolt diameter.

Finkenbinder (2007) used different criteria for determining the dowel embedment strength,

where the load at displacement limit of 19 mm (0.75 inch) was used for the capacity load.

Testing concluded when the dowel fully embedded into the material or when maximum load was

achieved.

Table: 4-4 Properties for TR-12 Model

LVL-1 LVL-2

Bolt Dia., mm (inch)

Bolt Dia., mm

(inch)

12.7 (0.5)

9.53

(0.38)

12.7

(0.5)

9.53

(0.38)

Dowel

Embedment

Strength

5% Offset

Yield,

MPa (psi)

AVG

26.1

(3780)

31.0

(4500)

35.0

(5070)

41.5

(6020)

COV (%) 13.12 12.9 9.73 14.4

Capacity,

MPa (psi)

AVG

38.8

(5620)

40.8

(5910)

42.9

(6220)

50.8

(7380)

COV (%) 13.92 11.61 11.18 12.79

Moisture Content, % AVG 9.88 9.87

COV (%) 4.54 5.13

Specific Gravity, % AVG 0.58 0.64

COV (%) 5.72 4.7

12.77 mm

(0.5 inch)

Bolt Dia.

5% Offset

Yield

AVG 596 (86.5)

COV (%) 3.04

Bolt

Bending

Strength,

Mpa (ksi)

Capacity AVG 724 (105)

COV (%) 1.51

9.53 mm

(0.38

inch) Bolt

Dia.

5% Offset

Yield

AVG 396 (57.3)

COV (%) 14.9

Capacity AVG 583 (84.6)

COV (%) 4.85

The moisture content (MC) and specific gravity (SG) for both LVL-1 and LVL-2 was found to

be similar with very low COV values. MC and SG values for LVL-2 were similar to that

obtained by Finkenbinder (2007). SG value for LVL-2 was 0.64 which was greater than 0.50 as

listed in manufacturers ESR report (ICC-ES 2005a).

66

The bolt bending test results at 5% offset yield and capacity from the cantilever beam test

showed the tensile yield strength to be much greater than minimum tensile yield strength 510

MPa (74.0 Ksi) for SAE bolts (Bickford 1998). For the 12.7 mm (0.5 inch) bolt, the strength was

724 MPa (105 Ksi), which was greater than 590 MPa (85.6 Ksi) as obtained by Finkenbinder

(2007). The strength obtained for the 9.53 mm (0.38 inch) bolt was 583 MPa (84.6 Ksi) .

4.5.3 NDS ASD Results

Table 4-5 shows the NDS ASD lateral design values from the allowable shear check as

mentioned in Equation 4-6, and from the TR-12 5% offset yield prediction. The connection

values in Table 4-5 are adjusted by applying load duration factor (1.6), reduction factor (5.0) and

group action factor (1.0) for the two bolt connections. Load duration factor of 1.6 was applied for

the calculation of both connection and shear values for adjusting to 10 minutes loading. For

consistency and safety adjustments, the TR-12 5% values were divided by a reduction term in

order to create a direct comparison on an allowable strength design basis. The adjusted allowable

lateral design value is the minimum of the connection and shear values.

Table: 4-5 NDS ASD Lateral Design Values Considering Connection Resistance and Allowable

Shear1

NDS ASD Lateral

Design Values, KN (lbs)

LVL-1 LVL-2



mm

(inch) 4D 7D 4D 7D 7D 4D 7D

12.7 (0.5) Connection

4.69

(1050)

4.68

(1050)

8.97

(2020)

9.51

(2140)

5.90

(1330)

10.80

(2430)

11.30

(2530)

Shear

0.75

(168)

4.0

(898)

4.0

(898)

11.65

(2620)

3.31

(744)

3.31

(744)

9.65

(2170)

9.525

(0.375) Connection

3.95

(888)

4.07

(914)

8.27

(1860)

9.18

(2060)

9.55

(2150)

10.50

(2360)

Shear

0.31

(71)

1.69

(379)

1.69

(379)

4.91

(1100)

1.40

(314)

4.07

(915)

1: Bold cells indicate controlling value of the two calculated, connection and shear values

Little variability was observed in the design values of either material for same set of variables.

Variability in the connection was low, from 3.95 KN (888 lbs) to 9.51 KN (2140 lbs) for LVL-1

67

and 5.90 KN (1330 lbs) to 11.30 KN (2530 lbs) for LVL-2, than that observed for values from

shear, that was from 0.31 KN (71 lbs) to 11.65 KN (2620 lbs) for LVL-1 to 1.40 KN (314 lbs) to

9.65 KN (2170 lbs) for LVL-2. The variability in distance “de” has direct effect on allowable

shear values (Equation 4-6). With increased in “de”, the allowable shear value increased. The

TR-12 5% values for two bolts were almost twice that of single bolt due to a multiplying factor

of 2.0 for two bolts.

In general, NDS lateral design values calculated from shear (Equation 4-6) controlled over the

connection resistance values except for the 12.7 mm (0.5 inch) two bolt, 7D loaded edge distance

configuration for LVL-1. For single bolt connections and 4D and 7D loaded edge distances, the

allowable shear values at 4D loaded edge distances were very low compared to the

corresponding connection resistance values due to the squared ratio of total depth less unloaded

edge distance to total depth ratio used in Equation 4-6. For single bolts, the loaded edge distance

considered was the same for both allowable shear and TR-12 5% offset yield equation. For two

bolt connections, the distance “de” in Equation 4-6 was from the most distant fastener to the

loaded edge, which was 3D more than the single connections. Finkenbinder (2007) also observed

allowable shear check values controlled over connection values for 4D loaded edge distance for

3:1 and 5:1 span: depth ratio, but the connection values controlled for the 10:1 span: depth ratio.

Table 4-6 shows the ratio of the tested to design capacity (T/DC) values that was designated as

Design Safety Factor (DSF). The lesser of the two calculated design capacities (shown in Table

5) was used. DSF would be a comparison between experimentally measured values and what an

engineer would calculate for the connection from current design practices.

Table: 4-6 Tested to Design Capacity Ratios for NDS ASD Lateral Design Values1

Ratio Test results to

NDS ASD Design

Capacity Values

LVL-1 LVL-2



mm (inch) 4D 7D 4D 7D 7D 4D 7D

12.7 (0.5) T/DC 14.70 3.01 5.53 2.81 4.49 5.38 2.75

COV (%) 11.9 14.10 6.22 15.30 9.51 14.70 22.50

9.53 (0.38) T/DC 29.20 5.60 9.90 4.03 10.20 4.61

COV (%) 5.01 8.38 9.13 19.00 12.20 20.10

68

1 T/DC – Ratio of Capacity values obtained from Connection Test to the calculated controlling

values from Table 5 to obtain Design Safety Factor (DSF)

DSF values were greater than 2.75 for all configurations and maximum for single bolt with 4D

loaded edge distances. Maximum values were 14.70 for the 12.7 mm (0.5 inch) bolt and 29.20

for the 9.53 mm (0.38 inch) bolt. The DSF for 7D loaded edge distances was comparatively less,

ranging from 2.75 to 5.60. DSF for 9.53 mm (0.38 inch) bolt at 4D loaded edge distances was

noted to be almost twice than that obtained for 12.7 mm (0.5 inch) bolt. The bolt diameter was

directly proportional to calculation of allowable shear value (Equation 4-6), making DSF

inversely proportional to the bolt diameter. DSF values for both LVL-1 and LVL-2 were found

to be similar for comparable sets and the DSF values for single bolt connections were more

conservative than two bolt connections, showing that material type had no set effect but number

of bolts inversely affected the DSF values.

4.5.4 TR-12 Capacity Results

TR-12 capacity values were calculated using the capacity values from dowel bearing strength

test and cantilever bolt bending test results from Table 4-4. Table 4-7 shows the predicted

capacity values for all test configurations with associated COV values from TR-12 equations

(AF&PA 1999). The capacity values were directly dependent on dowel bearing resistance and

main member bearing length values. Dowel bearing resistance values depend on dowel diameter

and embedment strength obtained in material testing as shown in Table 4-4. Therefore, only bolt

diameter and different dowel bearing capacities of different materials are the only variables that

affect the TR-12 capacity values. The capacity values for 12.7 mm (0.5 inch) bolt were greater

than the values for 9.53 mm (0.38 inch) bolt from all sets, where greater variability in values was

seen for LVL-1 than for LVL-2 due to lower value of average bearing length “lm“(refer Equation

4-2) for LVL-2 which was 38.1 mm (1.5 inch) than LVL-1 which had an average bearing length

of 44.5 mm (1.75 inch).

69

Table: 4-7: TR-12 Capacity Results

Capacity, KN (lbs)

LVL-1 LVL-2


Bolt Dia.

mm (inch)


4D 7D 4D 7D 7D 4D 7D

12.7 (0.5)

AVG

21.0

(4730)

22.46

(5050)

45.70

(10300)

40.6

(9120)

23.89

(5370)

40.9

(9200)

41.1

(9230)

COV (%) 15.9 7.46 18.2 11.7 10.4 8.7 7.12

9.525

(0.375)

AVG

17.22

(3870)

16.33

(3670)

34.60

(7780)

36.0

(8090)

37.0

(8320)

39.70

(8930)

COV (%) 4.93 13 9.2 15.3 14 11.2

There was no specific trend observed for a change in resistance with varying loaded edge

distance for both materials. Finkenbinder (2007) also did not observe any particular trend with

respect to variable loaded edge distance. The capacity resistance was observed to increase with

increase in number of bolts due to a multiplying factor of 2.0 for two bolt connections.

Table 4-8 shows the ratio of calculated to test (C/T) results for TR-12 model equations at

capacity. An accurate model prediction was defined as a C/T value of 0.85 to 1.15. C/T values

for 4D loaded edge distance values were greater than at 7D loaded edge distances, and single

bolt C/T values were greater than two bolt C/T values for both materials for comparable

configurations. No specific trend of C/T values was observed with respect to different bolt sizes.

C/T ratio shows a comparison of the model results.

o C/T < 0.85 : model prediction was conservative

o C/T ≈ (0.85 to 1.15) : model prediction was accurate

o C/T > 1.15 : model over predicted

70

Table: 4-8: C/T Ratio for TR-12 at Capacity

Calculated /Test, ratio

at Capacity

LVL-1 LVL-2


Bolt Dia.

mm (inch)


4D 7D 4D 7D 7D 4D 7D

12.7 (0.5)

C/T 1.74 1.13 1.90 1.17 1.17 1.97 1.29

COV (%) 11.4 9.34 20 12.7 12.6 9.6 6.3

9.525

(0.375)

C/T 1.63 1.01 1.92 1.36 2.36 1.69

COV (%) 7.16 17.7 13.6 19.3 13.2 15.2

In general these C/T ratios show that the model best predicts at 7D loaded edge distance for

single bolt configuration and over predicts for all other configurations. A decrease in predicted

C/T values was observed with an increase in loaded edge distance. This conclusion was

confirmed by Finkenbinder (2007), which showed over prediction at 4D, best prediction at 7D,

and under prediction at 10D loaded edge distances for single bolt connections for all span: depth

ratios. Predicted C/T values increased with increase in the number of bolts.

4.5.5 Statistical Comparison for TR-12 Model

Table 4-9 presents the statistical comparison of the C/T ratios at capacity for variable materials,

loaded edge distances, number of bolts, and bolt size. Comparisons used a single factor repeated

measure analysis of variance (ANOVA), with alpha (α = 0.05). If the null hypothesis was

rejected (p-value < 0.05), a Tukey’s Honestly Significant Difference (HSD) multiple comparison

was performed to obtain the relationship between the data set averages.

71

Table: 4-9 Statistical Comparison of C/T Ratios at Capacity

Bolt

Diameter,

mm (inch)

Fixed Variables Compared

Variables

Capacity

ANOVA,

p-value

Tukey’s

Conclusion

12.7 (0.5) LVL-1, 1 BOLT 4D & 7D 0.0000 4D>7D

LVL-1, 2 BOLT 4D & 7D 0.0000 4D>7D

LVL-2, 2 BOLT 4D & 7D 0.0000 4D>7D

1 BOLT, 7D LVL-1 & LVL-2 0.4980 ND

2 BOLT, 4D LVL-1 & LVL-2 0.6220 ND

2 BOLT, 7D LVL-1 & LVL-2 0.0360 LVL-2 > LVL-1

9.525 (0.375) LVL-1, 1 BOLT 4D & 7D 0.0000 4D>7D

LVL-1, 2 BOLT 4D & 7D 0.0000 4D>7D

LVL-2, 2 BOLT 4D & 7D 0.0000 4D>7D



For the 12.7 mm (0.5 inch) bolt, no significant difference was found between the C/T ratios of

LVL-1 and LVL-2 for the single bolt at 7D loaded edge distances and for two bolt at 4D loaded

edge distances. However, C/T ratios of LVL-2 were significantly greater than LVL-1 for two

bolts at 7D loaded edge distances. For the 9.525 mm (0.375 inch) bolt, the C/T ratios of LVL-2

was significantly greater than LVL-1 for two bolt at 4D and 7D loaded edge distances.

A consistent trend is greater C/T value at 4D loaded edge distances for both materials and bolt

diameters for single and two bolts. This trend would be due to the decreased test resistance at 4D

loaded edge distances with respect to the relatively stable calculated theoretical values for

variable loaded edge distances. Finkenbinder (2007) also observed a similar trend of

significantly greater C/T values for 4D samples compared to 7D and 10D loaded edge distance

samples.

4.6 Conclusions

The objective of this paper was to validate the TR-12 model equations using the experimental

results obtained from measuring properties from single and two bolted connections loaded

perpendicular to grain in double shear. Connection testing of single and two bolted connections

loaded perpendicular to grain showed splitting failure with mixed mode of crushing in the main

72

member (Im) and plastic moment in the fastener (IIIs) at 4D and 7D loaded edge distances for

both 12.7 mm (0.5 inch) and 9.525 mm (0.375 inch) bolt sizes. Splitting often occurred at the top

bolt, indicating greater load was carried by the top bolt. Considering this behavior, the two bolt

configurations may actually have an additional 3D distance from the loaded edge. Connection

resistance was observed to increase with increased loaded edge distance and number of bolts. In

general, the allowable shear check value controlled the NDS ASD lateral design value and for

single bolt at 4D loaded edge distances was highly conservative. The 5% TR-12 values

controlled over allowable shear check values for only one set of 7D loaded edge with two bolt

connections. The allowable shear values increased with increase in loaded edge distances where

the connection values did not have any marked effect with respect to loaded edge distance as the

connection values depended on the calculated dowel bearing strength of the main member. DSF

values showed a conservative prediction for all configurations and were inversely proportional to

the bolt diameter where shear values controlled. Material type did not show any effect on the

DSF values. Comparing test results with TR-12 results at capacity, the model best predicted at

the 7D loaded edge distances for single bolt configurations and over prediction for all other

configurations. Predicted C/T values for single bolt were greater than two bolt connections. C/T

ratios for LVL-2 were significantly greater than LVL-1 at 7D loaded edge distances for two bolts

connection configuration. Significant differences were found in the C/T values for variable

loaded edge distances showing a consistent trend of greater C/T values for 4D loaded edge

distances for both materials and bolt diameters for single and two bolts.

4.7 References

ASTM D 5652-95. 2005a. Standard Test Methods for Bolted Connections in Wood andWood-

Based Products. American Society of Testing and Materials, West Conshohocken, PA.

ASTM D 5764-97a. 2005b. Standard Test Method for Evaluating Dowel-Bearing Strength of

Wood and Wood-Based Products. American Society of Testing and Materials, West

Conshohocken, PA

American Forest and Paper Association (AF&PA). 1999. General Dowel Equations for

Calculating Lateral Connection Values – Technical Report 12. American Forest and

Paper Association, Washington, D.C.

American Forest and Paper Association (AF&PA). 2005. National Design Specification for

Wood Construction. American Forest and Paper Association, Washington, D.C.

73

Albright, D.G. 2006. The Effects of Bolt Spacing on the Performance of Single-Shear Timber

Connections Under Reverse-Cyclic Loading. M.S. Thesis. Virginia Polytechnic Institute

and State University. Blacksburg, VA. 290 p.

Bickford, J.H. and S. Nassar. 1998. Handbook of Bolts and Bolted Joints. CRC Press. Boca,

Raton, FL. 911p.

Billings, M.A. 2004. Investigation of the Effects of Spacing Between Bolts in a Row in a Single-

Shear Timber Connection Subjected to Reverse Cyclic Loading. M.S. Thesis. Virginia

Polytechnic Institute and State University. Blacksburg, VA. 264 p.

Eco-Link. 2001. Engineered Wood Products, Volume 11, Number 14,

http://www.forestinfo.org/Products/eco-links/CanadasForests.pdf, (August 12th

2009)

Finkenbinder, D. 2007. An Experimental Investigation of Structural Composite Lumber Loaded

by a Dowel in Perpendicular to Grain Orientation at Yield and Capacity. M.S. Thesis,

Virginia Polytechnic Institute and State University. Blacksburg, VA 198p.

Hindman, D.P., D. Finkenbinder, J.R. Loferski, P. Line. 2009. Predicting the Strength Of SCL

Dowel Connections Loaded Perpendicular to Grain: NDS Design Equation.

International Code Council Evaluation Services (ICC-ES) 2008a. ESR-1040 ICC Evaluation

Service, Inc, http://www.icc-es.org/reports/pdf_files/ICC-ES/ESR-1040.pdf, (August 12th

, 2009)

International Code Council Evaluation Services (ICC-ES) 2008b. ESR-1533 ICC Evaluation

Service, Inc., http://www.icc-es.org/reports/pdf_files/ICC-ES/ESR-1533.pdf, (August 12th

2009)

Jensen, J.L, P.J. Gustafsson, and H.J. Larsen. 2003. A Tensile Fracture Model for Joints

with Rods or Dowels Loaded Perpendicular to Grain. CIB-W18 meeting thirtysix,

paper 36-7-9, Colorado, USA.

Johansen, K.W. 1949. Theory of Timber Connection. International Association for Bridge

and Structural Engineering Publication, Vol. 9, 249-262.

Ramskill, T.E. 2002. Effect of Cracking on Lag Bolt Performance. Ph.D. dissertation. Virginia


Reshke, R.G. 1999. Bolted Timber Connections Loaded Perpendicular-to-Grain. Ph.D.

dissertation. Royal Military College of Canada. Kingston, Ontario. 294 p.

Smith, I., and G. Foliente. 2002. Load and Resistance Factor Design of Timber Joints:

International Practice and Future Direction, Journal of Structural Engineering, ASCE,

128(1): 48-59.

Van der Put, T.A.C.M. and A.J.M. Leijten. 2000. Evaluation of Perpendicular to Grain

74

Failure of Beams Caused by Concentrated Loads at Joints. CIB-W18 meeting

thirty-three, paper 33-7-7, Delft, The Netherlands.

Zahn, J.J. 1991. Design Equation for Multiple Fastener Wood Connections, Journal of Structural

Engineering, ASCE, Vol. 117 (11): 3477-3486

75

CHAPTER 5: RESULTS AND DISCUSSION: Comparison of Single and Two Bolted LVL

Perpendicular to Grain Connections: Fracture Models

This chapter includes the objective of measuring properties from single and two bolted

connections loaded perpendicular to grain in double shear for LVL from two different

manufacturers and comparing the connection test resistance to fracture based models and design

literature including Van der Put & Leijten (2000), Jensen et al. (2003), and Eurocode-5 (ENV

2005-1-1, 2004). The chapter is written in a form of a paper to be submitted to the ASCE Journal

of Materials in Civil Engineering.

5.1 Abstract

Previous research for perpendicular to grain connections has revealed brittle failure by splitting.

The purpose of this paper was to predict the connection behavior of one and two bolted

connections using two fracture models. Two different laminated veneer lumber (LVL) materials

were used along with two fracture mechanics models proposed by Van der Put and Jensen.

Experimental connection results were compared with these models and also with characteristic

and design splitting capacity equations from Eurocode-5. The values for two bolt connections

were greater than single bolt connections due to the “he” value for two bolts being 3D (spacing

between the two bolts) more than single bolt. LVL-1 had significantly greater predicted capacity

resistance values than LVL-2 for the same configuration due to greater fracture energy and

tension perpendicular to strength observed for LVL-1. The Mode-I fracture energy values

affected the predicted values of both the models, while the tension perpendicular to grain

strength values affected the Jensen model predictions. Connection configurations with greater

loaded edge distances produced greater characteristic and design splitting capacity values from

the Eurocode-5 design splitting equations. In general, all two bolted connection predictions were

conservative compared to single bolt connections for both bolt sizes. Comparison between a

yield-based model, Van der Put and Jensen models found that the Jensen model predicted the

best results while the Van der Put model over predicted the values. The yield-based model best

predicted for single bolt connection with 7D loaded edge distances for LVL-1, but over predicted

for all other configurations.

76

5.2 Introduction

The behavior and properties for connections in laminated veneer lumber (LVL) have not been

examined as extensively as solid wood materials. Finkenbinder (2007) studied single bolt

connections loaded perpendicular to the grain for solid sawn lumber, LVL and parallel strand

lumber (PSL). However, there is little research on multiple bolted connections, which are more

commonly used, loaded perpendicular to the grain. Smith and Foliente (2002) mention research

related to bolted connections, particularly with multiple bolts loaded in perpendicular to the grain

direction, is of a high priority.

The measured capacity of single and two bolted perpendicular to grain connections is reported in

Chapter 4 of this thesis. Comparisons of experimental results with General Dowel Equations for

Calculating Lateral Connection Values – TR-12 (AF & PA 1999) that assumes only a ductile

connection failure were performed. Smith et al. (2008) and Snow et al. (2004a and 2004b)

observed that the brittle and ductile failure mechanisms depend on connection geometries and

wood composite material used. As discussed in Chapter 4, brittle failure is a common occurrence

for dowels loaded perpendicular to the grain including splitting or crushing. To predict the

maximum load of these connections fracture models may be useful.

The purpose of this paper is to validate two fracture models used including Van der Put and

Leijten (2000), referred to as the Van der Put model, and Jensen et al. (2003), referred to as the

Jensen model. Model inputs and experimental capacity were found from measurements of single

and two bolted connections loaded perpendicular to grain in double shear. This paper compares

the connection test capacity values to the predicted values at capacity of the fracture models and

EC-5 design capacity values to obtain calculated to test (C/T) ratio and design safety factor

(DSF) values respectively. Also a statistical comparison between the C/T ratios at predicted

capacity values from the TR-12 model and the fracture model is shown.

5.3 Literature Review

The study of the formation and growth of cracks in materials is the basis of fracture mechanics

(Smith et. al. 2003). Fracture mechanics modeling has proved to be an effective tool in predicting

the brittle failure of cracked components under applied loads. Fracture mechanics has been

77

effectively applied to homogeneous isotropic materials, and may be useful for describing

orthotropic materials including wood and other fiber reinforced composites (Smith et al. 1999).

Failure of dowel joints under the influence of loads perpendicular to grain can be characterized

by bending of the fastener and/or embedment of the fastener in to the wood, or a brittle failure

that is characterized by splitting (also known as cracking) of the wood. Ductile failures are well

understood and accounted for by the European Yield Model (EYM), but brittle failures have

received little attention (Jensen 2003).

Three possible fracture modes considered include: Mode-I Opening/Tension, Mode-II In-Plane

Shear, and Mode-III Out of Plane Shear. Mode-I, for the purpose of research, is considered for

obtaining the fracture energy input value for fracture models used. Two models, one using

LEFM (Van der Put model), and one using quasi nonlinear fracture mechanics and based on

beam-on-elastic foundation (BEF) (Jensen model) were used to model the capacity resistance of

wood and wood composite materials.

The Van der Put and Leijten (2000) model was based on several assumptions including

neglecting normal forces in the cross section where stable splitting occurred. Crack propagation

was defined as the loss of potential energy due to splitting being equal to the required energy for

crack formation. The model also required fracture energy, Gf, to be of sufficient magnitude to

propagate the crack in both the length and width of the beam (Van der Put and Leijten 2000).

The general equation for splitting of the beam derived by Van der Put and Leijten (2000) is as

follows:

( ))1(6.0 α

α

−= f

fGG

hb

V

(Eqn: 5-1)

Where,

Vf = the maximum shear force at fracture, (N)

α = he / h = location of the dowel with respect to the loaded edge and the beam height

b = beam width, (mm) h = beam height, (mm)


G = shear modulus of the material, (N/mm2) Gf = fracture energy, (N/mm)

78

From additional analysis, Jensen (2003) showed little change in the results from Van der Put and

Leijten (2000) if the normal forces were included, hence justifying the assumption of neglecting

those normal forces. Also, a simplified assumption of Gf based on only Mode I, instead of a

combined mixed mode of Mode I and Mode II interaction was stated as a reasonable

approximation by Finkenbinder (2007). An alternative form of equation for the Van der Put

model is as follows:

α

α

−=

11C

hb

V f where,

6.01

fGGC = (Eqn: 5-2)

Results from Ehlbeck et al. (1989), Ballerini (1999), Reshke (1999) and Reffold et al. (1999)

who tested dowels loaded perpendicular to grain, with double shear connections in simply

supported beams were used to calibrate the C1 value such that C1 = 10 N/mm1.5

(Van der Put and

Leijten 2000). Equation 5-2 can be simplified to Equation 5-3 assuming a standard relationship

for G, Gf, which is unique to solid sawn lumber.

α

α

−=

110

hb

V f (Eqn: 5-3)

Snow et al. (2004b) measured laminated strand lumber (LSL) connections and found the Van der

Put model was relatively accurate. LSL connection failed in bending rather than splitting, which

was observed for LVL and PSL by Snow et al. (2004a). In both the above mentioned projects,

the diameter of the dowel was 19 mm (0.75 inch) and the main member depth was 88.9 mm (3.5

inch) thereby decreasing the loaded edge distance to 2.33D, which is much less than the required

minimum considerations, equal to 4D, as mentioned in the National Design Specification

(AF&PA 2005).

Jensen et al. (2003) developed a model based on the beam-on-elastic foundation (BEF) theory

which can be “applied to plates with edge dowels, to beams with dowels, and to beam splice

joints made of rods glued in a long grain” (Jensen et al. 2003). The model provided a complete

derivation using conventional stress method, finite element solution, and experimental

validation. The non-linear damage and fracture performance of wood is presented as “a linear

response that is equivalent in terms of peak stress, ft, and fracture energy dissipation, Gf…

Failure was assumed to occur when the maximum stress equaled the tensile strength

79

perpendicular to grain, ft” (Jensen et al. 2003). The Jensen model equation for splitting about a

dowel connection is given in Equation 5-4 (Jensen et al. 2003).

efLEFMPP hGGbPP

3

20, µµ ==

(Eqn: 5-4)

Where,

1

12

+

+=

ζ

ζµ and

2

2))(

3

5(

te

f

fh

EG

E

G=ζ

Where,

b = beam width, mm.

he = distance of the most distant fastener from the loaded edge, mm.

G = shear modulus of the material, N/mm2,

Gf = fracture energy perpendicular to grain (mode I), N/mm

E = modulus of elasticity of the material, N/mm2,

ft = tensile strength perpendicular-to-grain, N/mm2

PP, LEFM = the failure load as a LEFM solution, N, PP = the failure load, N

For determining the accuracy of the derivation based on BEF theory, Jensen et al. (2003)

performed a finite element analysis of a ‘symmetrical beam with one or more dowels’. The

model found a good correlation between the theoretical predictions and experimental results

when applied to experimental glulam beam results from Yasumura (2001), Quenneville and

Mohammad (2001), and Kasim and Quenneville (2002). The model was found to over predict

the results for larger loaded edge distances (Jensen et al. 2003).

The European design code Eurocode-5 (EC-5) applies to the design of buildings, timber in civil

engineering, and concerns with the requirements for mechanical resistance, serviceability,

durability and fire resistance of timber structures. EC-5 has a specific check of the splitting

capacity for perpendicular to the grain connections in softwoods denoted in Section 8, as

Equations 8.4 and 8.5 (ENV 2005-1-1, 2004).

h

h

hbwF

e

e

Rk

−

=

1

14,90 (Eqn: 5-5)

80

Where, w = maximum of

35.0

100

plw or 1, for punched metal plate fasteners and

w = 1, for all other fasteners

Where,

F90,Rk = the characteristic splitting capacity, (N) w = modification factor for fastener type

he = loaded edge distance of the most distant fastener, (mm)

h = member height, (mm) b = member width, (mm)

wpl = width of the punched metal plate fastener parallel to the grain, (mm)

Section 2.4.3 of EC5 relates the characteristic value (F90,Rk) to the design value (F90,Rd), along

with accounting for the material type, load duration, and moisture content effects (ENV 2005-1-

1, 2004) (Equation 5-6).

=

M

Rk

Rd

FkF

γ90

mod,90

(Eqn: 5-6)

Where,

F90,Rd = design splitting capacity, (N)

γM = partial factor for material properties = 1.3 for connections

kmod = modification factor considering load duration and service moisture content

= 0.9 for solid wood/LVL under a short term load (less than one week) with moisture

content not exceeding 20%

5.4 Materials and methods

The materials tested for this research were LVL from two different manufacturers. The first LVL

was from Georgia Pacific known as GP Lam LVL® which was rated as 2.0E and was made from

yellow poplar (Liriodendron tulipifera) and southern pine (Pinus spp.) veneers (ICC-ES 2008b),

and was designated as LVL-1 for this research. The dimensions of LVL-1 were 44.5 mm (1.75

inch) thick by 184 mm (7.25 inch) wide. The second LVL, designated as LVL-2, was from Boise

known as VERSA-LAM® which was rated as 3100f-2.0E and was made from southern pine

(Pinus spp.) and eucalyptus (Eucalyptus spp.) veneers, where the majority of the material was

81

southern pine (ICC-ES 2008a and Finkenbinder 2007). The dimensions of LVL-2 were 38.1 mm

(1.5 inch) thick by 184 mm (7.25 inch) wide.

Bolts used for testing were of diameters 12.7 mm (0.5 inch) and 9.53 mm (0.38 inch), 108 mm

(4.25 inch) long, low carbon steel, SAE J429 Grade 2 hex head bolts. The minimum tensile yield

strength (Fe) for SAE (Society of Automotive Engineers) bolts is listed as 510 N/mm2 (74,000

psi) (Bickford 1998). All bolts were ordered together from the supplier to ensure that bolts of

each size were from the same batch and thereby minimize the chances of variation in the bolts.

Chapter 4 of this thesis describes an experimental testing of connection test configurations with

4D and 7D loaded edge distances with 12.7 mm (0.5 inch) and 9.53 mm (0.38 inch) bolt sizes for

single and two bolt connections. The tests were done for two LVL materials from different

manufacturers for a fixed span: depth ratio of 3:1. The connection test results at capacity

compared with results at capacity obtained from the fracture models in this paper were from the

same paper.

5.4.1 Material tests

Material testing was performed to obtain input values for Equations 5-1 through 5-4 to predict

connection behavior from the Van der Put and Jensen models. The material testing included

shear modulus (G), modulus of elasticity (E), Mode I fracture energy and tension perpendicular

to the grain strength. The E and G testing was performed on 2180 mm (86 inch) long specimens

before cutting them down to 711 mm (28 inch) long specimen for connection testing. This was

due to minimum span requirement of 8 times the depth for E and G testing.

The torsion test outlined by ASTM D 198-05, Standard Test Methods of Static Tests of Lumber

in Structural Sizes (ASTM 2005b) was referred to obtain the shear modulus. Previous research

from Harrison (2006) and Finkenbinder (2007) used a modified method for the calculation of

shear modulus for wooden composites. The specimen was fixed at one end and a torque was

applied at the other end and the angular deflection was measured with help of clinometers

located at symmetric points along the length of the specimen. The testing setup consisted of a

MTS universal testing machine torsion actuator with a capacity of 5650 N-m (50,000 inch-lb.)

82

with a 56.5 N-m (500 inch-lb.) sensitivity and a fixed grip at the other end as shown in Figure 5-

1.

Figure 5-1: Shear Modulus Testing

All specimens were tested at a gage length defined as the distance between the two clinometers.

Two Accustar® II/DAS 20 Dual Axis Clinometers (20 degrees rotation range, 0.01 degrees

sensitivity) were used to measure the angular deflection. These clinometers were placed at 406

mm (16 inch) from each end according to the ASTM D 198 provisions (ASTM 2005b). The gage

length between these two clinometers was 813 mm (32 inch). A torsional loading rate of 0.5

degrees per minute up to an angular deflection limit of two degrees was used in accordance with

Finkenbinder (2007) to ensure the loading was in the elastic range and to prevent permanent

deformation. The following equation from ASTM D 198-05 was used for the purpose of shear

modulus calculations:

� � � !"#$%&' �()& ��*�+,��

- ./ (Eqn: 5-7)

Where,

G = shear modulus (psi.)

L = member gage length (inch), (distance between clinometers)

b = thickness of member (inch) h = height of member (inch)

λ = St. Venant constant T/θ = slope from torque-angle curve (lb-inch/radian)

θ = θ1-θ2 = change in angle between clinometers (radian)

T = torque at proportional limit

83

The flexure test outlined by ASTM D 198-05, Standard Test Methods of Static Tests of Lumber

in Structural Sizes (ASTM 2005b) was followed for the measurement of the E. Simply supported

specimens were loaded at mid span and the deflection was measured at mid span using an

LVDT. The same specimens from the shear modulus test were used for the MOE testing. The

testing setup consisted of a MTS universal testing machine of 245 KN (55,000 lbs) capacity

fitted with a load cell of 22.2 KN (5,000 lbs) attached to the load head. A yoke with an LVDT

was used to measure the deflection at center of the specimen. The clear span between the

supports was 2030 mm (80 inch) which was in accordance with the ASTM D 198-05

requirements for “beams intended primarily for evaluation of flexural properties” that specifies

that the span: depth ratio has to be between 5:1 and 12:1 (ASTM 2005b). The specimens were

loaded to 6670 N (1500 lbs) at the rate of 5.08 mm/min (0.20 inch/min) to obtain a load

deflection curve for MOE calculation but prevent permanent damage.

Figure 5-2: Modulus of Elasticity Test

Similar to the shear modulus testing, MOE testing used three repetitions per specimen and the

average apparent modulus of elasticity was calculated from the following equation:

∆=

I

LPE f

48

3

(Eqn: 5-8)

Where,

Ef = apparent modulus of elasticity (psi) L = span (inch)

I = moment of inertia (01234) P/∆ = slope of load-deflection data (lb/inch)

84

The average shear modulus values from the Equation 5-7 were used in the Equation 5-9 to

calculate average true modulus of elasticity.

−=

2

2111

L

h

KGEE f

(Eqn: 5-9)

Where,

Ef = average apparent material modulus of elasticity (psi)

E = average true material modulus of elasticity (psi)


G = average shear modulus (psi) h = height of beam (inch) L = length of beam (inch)

The procedure of ASTM D 143-94, Standard Test Methods for Small Clear Specimens of Timber

(ASTM 2005a), was followed for determining tension perpendicular to grain strength.

Specimens were cut as shown in Figure 5-3(a) from a part of the cross section undamaged by

splitting or crushing. Specimen size used for testing was 63.5 mm x 50.8 mm x 44.5 mm (2.5

inch x 2 inch x 1-.75 inch) for LVL-1 and 63.5 x 50.8 x 38.1 mm (2.5 inch x 2 inch x 1.5 inch)

for LVL-2, as compared to the ASTM D 143-94 recommended size of 63.5 mm x 50.8 mm x

50.8 mm (2.5 inch x 2 inch x 2 inch). The difference was due to the width of material used for

this research. A specimen was cut from all of the 130 connection test specimens. Speed of testing

was 2.54 mm/min (0.10 inch/min) as mentioned in ASTM D 143-94 until the ultimate load was

reached (ASTM 2005a). Specimens were placed in a test setup as shown in Figure 5-3(b).

(a) (b)

Figure 5-3: Tension Perpendicular to Grain Strength Test

85

Load-displacement curve data was recorded from the test results and the ultimate tension

perpendicular to grain stress was determined from the analysis of this curve, pertaining to the

following equation.

ft = Pmax/A (Eqn: 5-10)

Where,

ft = tension perpendicular to grain strength (psi)

Pmax = maximum load from load-displacement curve (lbs)

A = failure cross sectional area of specimen (in2)

There are no specific standards available for testing fracture properties of wood composites,

when this research was performed. However several assumptions and methods successfully

implemented by previous researchers for similar cases have been used. The ASTM D 5045-99,

Standard Test Methods for Plane-Strain Fracture Toughness and Strain Energy Release Rate of

Plastic Materials (ASTM 2005d) and ASTM E 399-90, Standard Test Method for Plane-Strain

Fracture Toughness of Metallic Materials (ASTM 2005c) standards were considered. These

methods were not followed exclusively as they are for metal and plastic materials which are

isotropic and homogeneous whereas as LVL is not (Ramskill 2002) and (Finkenbinder 2007).

Fracture test specimens were cut from all 130 connection test specimens and Mode-I test was

performed as shown in Figure 5-4.

(a) (b)

Figure 5-4: Mode I Test, (a) Specimen, (b) Mode I Test

An MTS universal testing machine with a load cell of 44.5 KN (10000 lbs) capacity was used for

testing. Rate of loading of 1.9 mm/ min (0.075 inch/min) was adopted from Finkenbinder (2007)

that allowed the specimen to fracture in 6-9 minutes range. The tests were ended when the load

86

reduced to 95% of the maximum load. The Mode I fracture energy was then obtained from the

following equation (Finkenbinder 2007):

A

WG If =

(Eqn: 5-11)

Where,

GIf = Mode I Fracture energy (lb-in/in2) W = area under the load v/s displacement curve (lb-in)

A = area of total crack propagation (in2)

The area (A) is determined by multiplying the average length of the crack with the thickness (B

= 44.5 mm (1.75 inch)). The average length of the crack is obtained by measuring the horizontal

projection made by it.

5.5 Results and Discussion

5.5.1 Material Property Results

Table 5-1 shows the material property results for input values in the Van der Put and Jensen

models. Shear modulus and MOE values for both the materials were similar, and both MOE

values were greater than given product ratings by 20%. Mode-I fracture energy and tension

perpendicular to grain strength for LVL-1 was greater than the values from LVL-2. Coefficient

of variation (COV) for LVL-1 were greater than LVL-2, except for the tension perpendicular to

grain strength, where LVL-2 showed a greater COV. Mode-I fracture energy and tension

perpendicular to grain strength of LVL-1 were greater than LVL-2 by 18.1% and 61.1%,

respectively. All LVL-2 material values compared well with results from Finkenbinder (2007).

The tension perpendicular to grain strength was greater than the value from Finkenbinder (2007)

but was still considered acceptable.

87

Table: 5-1: Material Property Results

PROPERTY MATERIAL %

Diff. LVL-1 LVL-2

Mode-I Fracture Energy,

N-m/m^2 (lb-in/in^2)

AVG 1340 (7.66) 1130 (6.46) 18.5

COV (%) 7.56 5.57

Modulus Of Elasticity,

MPa (psi)

AVG

16500

(2390000)

16550

(2400000) -0.03

COV (%) 12.16 7.5

Shear Modulus, MPa

(psi)

AVG

703

(102000)

689

(100000) 2.03

COV (%) 12.75 8.82

Tension Perpendicular to

Grain Strength, MPa

(psi)

AVG 1.60 (232) 0.99 (144) 61.1

COV (%) 17.95 25.14

5.5.2 Fracture model results

Equations 5-1 and 5-4 were used for the calculation of theoretical capacity resistance for Van der

Put and Jensen models respectively. The average values of G and E, and each individual

specimen value for Mode-I fracture energy and tension perpendicular to grain strength was used

as inputs. Table 5-2 shows theoretical capacity values for Van der Put and Jensen models with

corresponding COVs. Average capacity resistance values for the Van der Put model ranged from

29.50 KN (6640 lbs) to 68.10 KN (15300 lbs) for 12.7 mm (0.5 inch) bolt size, and from 24.10

KN (5410 lbs) to 48.10 KN (10800 lbs) for 9.53 mm (0.38 inch) bolt size. Average capacity

resistance values for Jensen model ranged from 17.10 KN (3850 lbs) to 30.6 KN (6880 lbs) for

12.7 mm (0.5 inch) bolt size, and from 14.60 KN (3280 lbs) to 26.4 KN (5934 lbs) for 9.53 mm

(0.38 inch) bolt size. The values predicted by Van der Put model were greater than those

predicted by Jensen model for similar set configurations.

88

Table: 5-2: Fracture Model Results

Van der Put, Capacity,

KN (lbs)

LVL-1 LVL-2


Bolt Dia.

mm (inch)


4D 7D 4D 7D 7D 4D 7D

12.7 (0.5)

AVG

29.50

(6640)

45.40

(10200)

45.40

(10200)

68.1

(15300)

37.50

(8430)

38.2

(8580)

57.4

(12900)

COV (%) 3.12 3.18 4.7 4.39 6.04 4.26 3.2

9.53

(0.38)

AVG

24.10

(5410)

37.20

(8360)

37.20

(8360)

48.1

(10800)

29.0

(6520)

39.9

(8970)

COV (%) 5.87 2.82 3.42 6.96 3.36 2.77

Jensen, Capacity, KN

(lbs)

LVL-1 LVL-2


Bolt Dia.

mm (inch)


4D 7D 4D 7D 7D 4D 7D

12.7 (0.5)

AVG

17.10

(3850)

25.20

(5670)

25.8

(5790)

30.6

(6880)

18.50

(4150)

19.4

(4350)

22.7

(5100)

COV (%) 7.31 4.5 5.18 7.56 8.23 7.6 10.3

9.53

(0.38)

AVG

14.60

(3280)

21.90

(4930)

22.4

(5040)

26.4

(5934)

15.7

(3520)

19.7

(4420)

COV (%) 7.94 3.67 4.31 4.28 4.48 7.4

For both the fracture models and bolts sizes, the least capacity value was obtained for LVL-1

single bolt at 4D loaded edge and the greatest capacity value was obtained for LVL-1 two bolt at

7D loaded edge. COVs for both the models were within 10% for all sets. As loaded edge

distance increased, the capacity resistance calculated by both models increased since the loaded

edge distances is a variable in both models and has a direct effect on the predicted capacity

values. The prediction at 7D loaded edge distance for single bolt and at 4D loaded edge distance

for two bolt are observed to be similar due to the “he” value being the same for both the cases.

Differences observed between these average values were due to the use of individual specimen

material properties as inputs for the fracture model equations.

LVL-1 had greater predicted capacity resistance values than LVL-2 for the same sets for both

models due to the greater Mode I fracture energy and tension perpendicular to grain strength

measured for LVL-1 in (Table 5-1). Predicted capacity resistance values for the 12.7 mm (0.5

89

inch) bolts were greater than the corresponding 9.53 mm (0.38 inch) bolt size configurations in

every case due to the decreased loaded edge distance, since the NDS spacing requirement used

for connection testing, is a function of dowel diameter “D” (AF & PA 2005).

Table 5-3 shows the ratio of calculated to test (C/T) results for fracture models equations at

capacity. The calculated values are from Table 5-2 above and the test values are from Chapter 4.

C/T ratios allow for an easier comparison of the predicted values and the following deductions

were made for C/T values. The accurate prediction range was considered to be from 0.85 to 1.15

to be consistent with Chapter 4.

o C/T < 0.85 : model under predicted or predicted conservatively

o C/T ≈ (0.85 to 1.15) : model prediction was accurate

o C/T > 1.15 : model over predicted

Table: 5-3 C/T Ratio for Fracture Models at Capacity

Van der Put, C/T ratio

at Capacity

LVL-1 LVL-2


Bolt Dia.

mm (inch)

Loaded Edge Distance

Loaded Edge

Distance

4D 7D 4D 7D 7D 4D 7D

12.7 (0.5)

C/T 2.48 2.29 1.88 1.98 1.84 1.84 1.81

COV (%) 12.8 8.43 8.09 11.9 10.5 4.5 6.17

9.53 (0.38)

C/T 2.27 2.3 2.02 1.81 1.87 1.69

COV (%) 6.93 12 7.73 14 16.1 5.93

Jensen, C/T ratio at

Capacity

LVL-1 LVL-2


Bolt Dia.

mm (inch)

Loaded Edge Distance

Loaded Edge

Distance

4D 7D 4D 7D 7D 4D 7D

12.7 (0.5)

C/T 1.43 1.27 1.07 0.89 0.9 0.93 0.71

COV (%) 9.68 8.34 7.21 13.8 9.61 6.94 8.61

9.53 (0.38)

C/T 1.37 1.36 1.23 1 1 0.83

COV (%) 3.69 11.2 7.05 13.2 11.9 8.08

The Van der Put model over predicted capacity values for all connection test configurations. In

general, the Jensen models over predicted capacity values only for the LVL-1 single bolt

90

connections at both bolt sizes. Jensen model accurately predicted for all connection sets for

LVL-2 except for two bolt connection at 7D loaded edges for 12.7 mm (0.5 inch) bolt, where it

conservatively predicted. Jensen model over predicted only the 9.53 mm (0.38 inch) two bolt

connections at 4D loaded edge for LVL-1. The C/T ratios for LVL-1 were greater than LVL-2

for comparable connection test sets, due to greater Mode-I fracture energy of LVL-1. The C/T

ratios are observed to decrease with an increase in number of bolts for similar test sets.

5.5.3 Graphical Comparison of Fracture models and TR-12 model (Chapter 4)

Figure 5-5 shows a graphical comparison between the tree models used, Van der Put, Jensen and

TR-12. Figure 5-5 (a) shows comparisons for configurations with 12.7 mm (0.5 inch) diameter

bolts and Figure 5-5 (b) shows for 9.53 mm (0.38 inch) bolts. Figure 5-5 indicates that the Van

der Put model over predicts at capacity and the C/T values are consistent with changes in loaded

edge distance. The Jensen model C/T ratios over predicted for single bolt connection and

predicted well for the two bolt connection with respect to loaded edge distances. The TR-12

model showed accurate predictions at 7D loaded edge distances for single bolt connections and

over predicted for all other case.

Figure 5-5 indicates that for the TR-12 model the C/T values for LVL-2 are greater than LVL-1.

This was due to greater dowel bearing capacity of LVL-2 material which has a direct effect on

TR-12 model predictions (Equation 2-1 to 2-4). An opposite observation is seen for the fracture

models where the C/T ratio for LVL-1 are greater than LVL-2. This was due to greater Mode-I

fracture energy and tension perpendicular to grain strength values obtained for LVL-1 material.

91

(a) Comparison for 12.7 mm (0.5 inch) bolts

(b) Comparison for 9.53 mm (0.38 inch) bolts

Figure 5-5: Model Comparisons

In general Van der put and Jensen model showed consistency in prediction of capacity values

with respect to variable loaded edge distances and TR-12 showed greater predictions of capacity

values at 4D loaded edge compared to 7D loaded edge distances. This observation was similar to

that of Finkenbinder (2007) who also observed TR-12 model predictions at capacity to decrease

0.25

0.55

0.85

1.15

1.45

1.75

2.05

2.35

2.65

4D 7D 4D 7D

1 2

C/T

Ra

tio

Number of Bolts, Loaded Edge Distance

Model Comparisons - 1/2" BOLTS

TR-12,LVL-1

Van der Put, LVL-1

Jensen, LVL-1

TR-12, LVL-2

Van der Put, LVL-2

Jensen, LVL-2

0.25

0.55

0.85

1.15

1.45

1.75

2.05

2.35

2.65

4D 7D 4D 7D

1 2

C/T

Ra

tio

Number of Bolts, Loaded Edge Distance

Model Comparisons - 3/8" BOLTS

TR-12, LVL-1

Van der Put, LVL-1

Jensen, LVL-1

TR-12, LVL-2

Van der Put, LVL-2

Jensen, LVL-2

92

with increase in the loaded edge distances and fracture model predictions to remain constant. For

fracture models, C/T ratios at capacity for single bolt were greater than for two bolt connections

at both loaded edge distances; where as a reverse trend was observed for TR-12 model.

5.5.4 Eurocode-5 Results

Equations 5-5 and 5-6 were used to calculate the characteristic and design splitting capacities in

Table 5-4. The main member width and loaded edge distance are the only variables in Equations

5-5 and 5-6 that are affected by the test configurations used. LVL-1 had a greater design splitting

capacity for the same configurations as LVL-2 due to the increased member width.

Configurations with greater loaded edge distances produced greater characteristic and design

splitting capacity values for the same materials, bolt sizes and number of bolts. The prediction at

7D loaded edge distance for single bolt and at 4D loaded edge distance for two bolt were similar

due to the same “he” for both cases. The values for two bolt connections were greater than single

bolt connections due to the “he” value for two bolts being 3D (spacing between the two bolts)

more than single bolt. The equation used to obtain characteristic splitting strength is only for

softwood members (Porteous and Kermani 2007) and does not consider LVL.

Tabel: 5-4: Eurocode-5 Characteristic and Design Splitting Capacities

Characteristic

Splitting

Capacity, N

(lbs)

LVL-1 LVL-2


Bolt Diameter,

mm (inch)


4D 7D 4D 7D 7D 4D 7D

12.7 (0.5)

5210

(1170)

8160

(1830)

8160

(1830)

12600

(2830)

6990

(1570)

6990

(1570)

10800

(2430)

9.525 (0.375)

4310

(970)

6360

(1430)

6360

(1430)

8740

(1970)

5450

(1230)

7490

(1680)

Design Splitting

Capacity, N

(lbs)

LVL-1 LVL-2


Bolt Diameter,

mm (inch)


4D 7D 4D 7D 7D 4D 7D

12.7 (0.5)

3610

(811)

5650

(1270)

5650

(1270)

8720

(1960)

4840

(1090)

4840

(1090)

7470

(1680)

9.525 (0.375)

2990

(671)

4400

(990)

4400

(990)

6050

(1360)

3780

(849)

5190

(1170)

93

Table 5-5 shows the average EC-5 design safety factor (DSF) values, calculated as ratio of

experiment connection test capacity to the EC-5 predicted design splitting capacity. The factors

ranged from 3.37 to 4.31 for the 12.7 mm (0.5 inch) bolt size, and from 3.61 to 4.56 for the 9.525

mm (0.375 inch) bolt size. There was no particular trend observed with respect to variable bolt

sizes and materials. Except for two bolt connection for LVL-1 with 12.7 mm (0.5 inch) bolt size,

all 7D loaded edge configurations had greater DSF values than corresponding 4D loaded edge

configurations. Greater DSF values indicated a more conservative prediction. Table 5-5 shows

that all the configurations conservatively predict and that two bolted connections predicted more

conservatively than single bolt connections for both bolt sizes. DSF of 3.88 was obtained by

Finkenbinder (2007) for LVL material at 4D loaded edge distances for 3:1 span: depth ratio for

12.7 mm (0.5 inch) single bolt.

Table 5-5: Average EC-5 Design Safety Factor Values

Connection Test

Capacity/ EC-5

Design Capacity

LVL-1 LVL-2



mm

(inch) 4D 7D 4D 7D 7D 4D 7D

12.7 (0.5)

T/DC 3.37 3.56 4.31 4.13 4.06 4.11 4.12

COV (%) 11.3% 7.90% 5.73% 10.4% 6.32% 4.26% 5.69%

9.525

(0.375)

T/DC 3.61 3.66 4.07 4.56 4.03 4.39

COV (%) 7.06% 9.66% 6.02% 10.20% 12.4% 5.54%

5.5.5 Statistical comparison for Fracture Models

Table 5-6 represents the statistical comparison of C/T ratios at capacity from both fracture

models considering different materials, loaded edge distance, bolt diameter and number of bolts.

A single factor repeated measure analysis of variance (ANOVA), with alpha (α = 0.05) was used.

If the null hypothesis was rejected (p-value < 0.05), a Tukey’s Honestly Significant Difference

(HSD) multiple comparison was performed to obtain relation between compared set averages.

94

In general, for the Van der Put model no significant difference in the C/T ratios was found when

4D and 7D loaded edge distances and LVL-1 and LVL-2 materials were compared, except for

the two bolt 9.53 mm (0.38 inch) for LVL-1 where C/T ratios at 4D were significantly greater

than 7D loaded edge, and for single bolt 12.7 mm (0.5 inch) at 7D loaded edge distance where

C/T ratios for LVL-1 were significantly greater than LVL-2.

For the Jensen model the C/T ratios for 4D loaded edge distance and LVL-1 material were

significantly greater than 7D loaded edge distance and LVL-2 material respectively. Greater

Mode-I fracture energy and tension perpendicular to grain strength obtained for LVL-1 than

LVL-2 contributed for the greater C/T ratios for LVL-1. This conclusion was made on the basis

of a sample calculation that showed that greater Mode-I fracture energy and tension

perpendicular to grain strength values resulted in greater predicted values for both the fracture

models (Equation 5-1 and 5-4).

Table: 5-6: Statistical comparison of C/T ratios at capacity, considering test variables

Bolt

Diameter,

mm (inch) Fixed Variables

Compared

Variables

Van der Put Jensen

ANOVA,

p-value

Tukey's

Conclusion

ANOVA,

p-value

Tukey's

Conclusion

12.7 (0.5) LVL-1, 1 BOLT 4D & 7D 0.123 ND 0.010 4D>7D

LVL-1, 2 BOLT 4D & 7D 0.295 ND 0.000 4D>7D

LVL-2, 2 BOLT 4D & 7D 0.499 ND 0.000 4D>7D

1 BOLT, 7D

LVL-1 &

LVL-2 0.000

LVL-1 >

LVL-2 0.000

LVL-1 >

LVL-2

2 BOLT, 4D

LVL-1 &

LVL-2 0.448 ND 0.000

LVL-1 >

LVL-2

2 BOLT, 7D

LVL-1 &

LVL-2 0.055 ND 0.001

LVL-1 >

LVL-2

9.53

(0.38) LVL-1, 1 BOLT 4D & 7D 0.789 ND 0.743 ND

LVL-1, 2 BOLT 4D & 7D 0.034 4D>7D 0.000 4D>7D

LVL-2, 2 BOLT 4D & 7D 0.105 ND 0.001 4D>7D

2 BOLT, 4D

LVL-1 &

LVL-2 0.164 ND 0.000

LVL-1 >

LVL-2

2 BOLT, 7D

LVL-1 &

LVL-2 0.214 ND 0.003

LVL-1 >

LVL-2

95

Finkenbinder (2007) observed no significant difference between C/T ratios for LVL and PSL

materials with respect to variable loaded edge distances for Van der Put model, but did identify

significant differences for the Jensen model between the values from the 4D loaded edge

distance and 10D loaded edge distances.

5.5.6 Statistical comparison between TR-12 and Fracture models

Table 5-7 represents a statistical comparison of C/T ratios at capacity from TR-12 and both

fracture models, for variable materials with variable loaded edge distances for variable number

of bolts of variable size. TR-12 values are from chapter 4. Comparison for all thirteen

connection test set configurations was performed. A significant difference was found between

the three models for all sets.

Table: 5-7: TR-12, Van der Put and Jensen Model Comparison for Connection Capacity

LVL Bolt Dia.,

mm (inch)

Number

of Bolts

Loaded

Edge

ANOVA,

p-value

Tukey's Conclusion

LVL-1

12.7 (0.50)

1 4D 0.0000 Van der put > TR-12 > Jensen

7D 0.0000 Van der put > Jensen > TR-12

2 4D 0.0000 (Van der put & TR-12) > Jensen

7D 0.0000 Van der put > TR-12 > Jensen

LVL-2




LVL-1

9.53 (0.38)


7D 0.0000 Van der put > Jensen > TR-12



LVL-2

2 4D 0.0000 TR-12 > Van der put > Jensen

7D 0.0000 (Van der put & TR-12) > Jensen

In general average C/T ratios at capacity from the Van der Put model were significantly greater

than both the TR-12 and the Jensen model, except for two bolt connections at 4D loaded edge

distances, where no significant difference was found between Van der Put and TR-12 model. The

exception was configuration with two bolts of 9.53 mm (0.38 inch) connection for LVL-2 at 4D

loaded edge distance where TR-12 model C/T ratios were significantly greater than both Van der

Put and Jensen model.

96

Unlike Van der Put and TR-12 model comparison where no significant difference was found for

four two bolt configurations, all the configurations comparison between TR-12 and Jensen

showed a significant difference. For both materials and bolt sizes the average C/T ratios for TR-

12 model were significantly greater than Jensen model except for single bolt 7D loaded edge

configurations for LVL-1.

5.6 Conclusions

Two fracture mechanics models from Van der Put and Leijten (2000) and Jensen et al. (2003)

were compared with connection testing results using bolted LVL connections loaded

perpendicular to grain. Material input properties for the fracture models included shear modulus,

modulus of elasticity, Mode-I fracture energy, and tension perpendicular to grain strength.

Mode-I fracture energy and tension perpendicular to grain strength for LVL-1 were greater than

LVL-2. As loaded edge distance increased, the capacity resistance calculated by both fracture

models increased. The values for two bolt connections were greater than single bolt connections

due to the “he” value for two bolts being 3D (spacing between the two bolts) more than single

bolt. LVL-1 had significantly greater predicted capacity values than LVL-2 for the same

configurations due to greater fracture energy and greater tension perpendicular to grain strength

observed for LVL-1. The Mode-I fracture energy values affected the predicted values for both

models and the tension perpendicular to grain strength values affected the values of the Jensen

model. For the Eurocode-5 predictions, configurations with greater loaded edge distances

produced greater characteristic and design splitting capacity values for the same materials, bolt

sizes and number of bolts. In general, all the configurations showed conservative predictions

with two bolted connections predicting more conservatively than single bolt connections for both

bolt sizes. Comparing the two fracture models with a ductile model TR-12, Jensen model

predicted more accurate C/T ratios with respect to variable loaded edge distances, material,

number and size of bolts. The Van der Put model tended to over predict values, while the TR-12

model had no consistent trend in C/T ratios, but seemed to be affected inversely by changes in

loaded edge distance.

97

5.7 References

ASTM D 143-94. 2005a. Standard Test Methods for Small Clear Specimens of Timber.

American Society of Testing and Materials, West Conshohocken, PA.

ASTM D 198-05. 2005b. Standard Test Methods of Static Tests of Lumber in Structural Sizes.


ASTM E 399-90. 2005c. Standard Test Method for Plain-Strain Fracture Toughness of Metallic

Materials. American Society of Testing and Materials, West Conshohocken, PA.

ASTM D 5045-99. 2005d. Standard Test Methods for Plane-Strain Fracture Toughness and

Strain Energy Release Rate of Plastic Materials. American Society of Testing and

Materials, West Conshohocken, PA


Calculating Lateral Connection Values – Technical Report 12. American Forest and

Paper Association, Washington, D.C.

American Forest and Paper Association (AF&PA). 2005. National Design Specification

for Wood Construction. American Forest and Paper Association, Washington,

D.C.

Ballerini, M. 1999. A New Set of Experimental Tests on Beams Loaded Perpendicular to Grain

by Dowel Type Joints. CIB-W18 meeting thirty-two, paper 32-7-2, Graz, Austria.

Bickford, J.H. and S. Nassar. 1998. Handbook of Bolts and Bolted Joints. CRC Press. Boca,

Raton, FL. 911p.

Ehlbeck, J, R. Gorlacher, and H. Werner. 1989. Determination of Perpendicular to Grain Tensile

Stresses in Joints with Dowel-Type Fasteners – a Draft Proposal for Design Rules. CIB-

W18 meeting twenty-two, paper 22-7-2, Berlin, Germany.

ENV 2005-1-1 Eurocode-5. 2004. Design of Timber Structures, Part 1. Comite Europeen de

Normalisation, Brussels, Belgium

Finkenbinder, D. 2007. An Experimental Investigation of Structural Composite Lumber Loaded

by a Dowel in Perpendicular to Grain Orientation at Yield and Capacity. M.S. Thesis,

Virginia Polytechnic Institute and State University. Blacksburg, VA 198p

Hindman, D.P., D. Finkenbinder, J.R. Loferski, P. Line. 2009. Predicting the Strength Of SCL

Dowel Connections Loaded Perpendicular to Grain. Part II: Fracture Mechanics

Equation.


Service, Inc, http://www.icc-es.org/reports/pdf_files/ICC-ES/ESR-1040.pdf, (August 12th

, 2009)

98


Service, Inc., http://www.icc-es.org/reports/pdf_files/ICC-ES/ESR-1533.pdf, (August 12th

2009)

Jensen, J.L, P.J. Gustafsson, and H.J. Larsen. 2003. A Tensile Fracture Model for Joints with

Rods or Dowels Loaded Perpendicular to Grain. CIB-W18 meeting thirtysix, paper 36-7-

9, Colorado, USA.

Jensen, J.L. 2003. Splitting Strength of Beams Loaded by Connections. CIB-W18 meeting thirty-

six, paper 36-7-8, Colorado, USA.

Kasim, M. and J.H.P. Quenneville. 2002. Effect of Row Spacing on the Capacity of

Perpendicular to Grain Loaded Timber Joints with Multiple Timber Connections Loaded

Perpendicular to Grain. CIB-W18 meeting thirty-five, paper 35-7-6, Kyoto, Japan

Porteous J and Kermani A. 2007. Structural Timber Design to Eurocode-5, Blackwell Science

Ltd, a Blackwell Publishing Company, 542 p

Quenneville, J.H.P, and M. Mohammad. 2001. A Proposed Canadian Design Approach for

Bolted Connections Loaded Perpendicular to Grain. Joints in Timber Structures,

Proceedings of the International RILEM Symposium, Stuttgart, Germany.

Ramskill, T.E. 2002. Effect of Cracking on Lag Bolt Performance. Ph.D. dissertation. Virginia


Reffold, A., T.N. Reynolds, and B.S. Choo. 1999. An Investigation into the Tensile Strength of

Nail Plate Timber Joints Loaded Perpendicular to the Grain. Journal of the Institute of

Wood Science. 15(1).



Smith, I, N. Kharout, G. McClure. 1999. Fracture Modeling of Bolted Connections In Wood And

Composites, Journal of Materials in Civil Engineering, November 1999. 345-352

Smith, I., E. Landis, and M. Gong. 2003. Fracture and Fatigue in Wood. John Wiley &

Sons Ltd. Sussex, England. 234 p.

Smith, I, M. Snow, and A. Asiz. 2008. Failure Characteristics of Engineered Wood Products

Connections, World Conference on Timber Engineering, Miyazaki, Japan, 8p.

Snow, M., A. Asiz, and I. Smith. 2004a. Failure Behaviour of Single Dowel Connections in

Engineered Wood Products. 5th Structural Specialty Conference of the Canadian Society

for Civil Engineering. Saskatoon, Saskatchewan, Canada. 9 p.

99

Snow, M., I. Smith, and A. Asiz. 2004b. Dowel Joints in Engineered Wood Products:

Assessment of Simple Fracture Mechanics Models. CIB-W18 meeting thirtyseven, paper

37-7-15, Edinburgh, Scotland. 12 p.

Van der Put, T.A.C.M. and A.J.M. Leijten. 2000. Evaluation of Perpendicular to Grain Failure of

Beams Caused by Concentrated Loads at Joints. CIB-W18 meeting thirty-three, paper 33-

7-7, Delft, The Netherlands.

Yasumura, M. 2001. Criteria for Damage and Failure of Dowel-Type Joints Subjected to Force

Perpendicular to Grain. CIB-W18 meeting thirty-four, paper 34-7-9, Venice, Italy.

100

CHAPTER 6: SUMMARY AND CONCLUSIONS

6.1 Summary

Investigation of the behavior of single and two bolt connection configurations perpendicular

to grain in LVL was performed by comparing the results obtained from experimental analysis

of beams loaded perpendicular to grain at mid span by single and two bolt double shear

laterally loaded connections to theoretical predictions from the three models considered. The

specific objectives of the research included: measuring the properties from single and two

bolt connections loaded perpendicular to the grain in double shear, comparing connection

resistance to yield based model and design literature including TR-12 and NDS ASD and

comparing connection resistance to fracture based models and design literature including

Van der Put & Leijten (2000), Jensen et al. (2003), and Eurocode-5 (ENV 2005-1-1, 2004).

Required material property inputs for theoretical predictions by three models were also

measured as a part of testing procedure. The material property testing included shear

modulus, modulus of elasticity (MOE), dowel bearing strength, bolt bending, tension

perpendicular to grain, Mode-I fracture energy, specific gravity and moisture content. A total

of 130 connection tests were performed and the results at capacity were compared with the

theoretical predictions at capacity from the three models, comparing on the basis of

calculated to test (C/T) ratio. Factors of safety for NDS ASD and Eurocode 5 were calculated

by comparing design capacities to test (DC/T) ratio. Comparison between the three models

was also made by comparing C/T ratios for the configuration sets considered.

6.2 Conclusions

Conclusions made on the basis of the results obtained, are as follows:

6.2.1 Connection Test results

� Five types of failures were observed, splitting (denoted as ‘S’), Mode Im (crushing in the

main member), IIIs (single plastic hinge forming in the main member), and mixed failure

modes of S-Im and S-IIIs.

� Modes “Im” and “IIIs” only occurred twice for the two bolt connection (no split at bottom

bolt), for 7D loaded edge distance, for both bolt diameters and the mixed failures of “S-

IIIs”, dominated for all connection tests with the 3/8 inch bolt due to lower bolt diameter

for these tests, which would offer lower resistance to formation of a plastic hinge.

101

� In general Mode S was observed to dominate for all 4D loaded edge distance, and mixed

mode S-Im and S-IIIs dominated for 7D loaded edge distance for 1/2 inch bolts and 3/8

inch bolts respectively.

� Splitting often occurred at the top bolt, indicating greater load was carried by the top bolt.

Considering this behavior, the two bolt configurations may actually have an additional

3D distance from the loaded edge.

6.2.2 Material Test Results

� Shear modulus and MOE values were similar for LVL-1 and LVL-2, where MOE values

were greater than given product ratings by 20%. Moisture content and specific gravity

values for both materials were found to be similar with very low COV’s.

� Dowel embedment test results showed that LVL-2 had a greater resistance than LVL-1

for both bolt diameters at 5% offset yield and capacity and the bolt bending test results at

5% offset yield and capacity from the cantilever beam test showed the tensile yield

strength to be greater than minimum tensile yield strength 74.0 Ksi for SAE bolts

(Bickford 1998).

� Mode-I fracture energy and tension perpendicular to grain strength of LVL-1 was greater

than LVL-2 by 18.1% and 61.1%.

6.2.3 NDS ASD Prediction Results Comparisons

� In general, NDS lateral design values calculated from shear controlled over connection

resistance values for all sets, except the two bolts with 7D loaded edge distance

configuration for LVL-1.

� The allowable shear values at loaded edge distance of 4D were over 150% lower

compared to the values at 7D loaded edge distances for similar sets and for single bolt

connections the shear values at 4D loaded edge distances were over 500% lower to

corresponding connection resistance values due the squared ratio used in the Equation 2-

6(a) for calculation of shear value.

� Design safety factor (DSF) values were greater than 2.75 for all configurations and were

highly conservative for single bolt with 4D loaded edge distances. DSF for 3/8 inch bolt

at 4D loaded edge distances was noted to be almost twice than that obtained for 1/2 inch

bolt which would be due to bolt diameter being directly proportional to calculation of

102

allowable shear value as seen in the Equation 2-6(a), making DSF inversely proportional

to the bolt diameter.

� DSF values for both LVL-1 and LVL-2 were found to be similar for comparable sets and

the DSF values for single bolt connections were more conservative that for two bolt

connections, showing that material type had no set effect but number of bolts inversely

affected the DSF values.

6.2.4 EC-5 Prediction Results Comparison

� LVL-1 had a greater design splitting capacity for the same configurations as LVL-2 due

to the increased member width.

� Configurations with greater loaded edge distances produced greater characteristic and

design splitting capacity values for the same materials, bolt sizes and number of bolts due

to the direct dependence of loaded edge distance on the prediction of the characteristic

and design values.

� For the same set configuration, two bolt connections showed greater DSF values than

single bolt connections and there was no particular trend in DSF observed, with respect to

variable bolt sizes and materials.

6.2.5 TR-12 Model Capacity Result Comparison

� The capacity values for 1/2 inch bolt were greater than the values for 3/8 inch bolt from

all sets and there was no specific trend observed for increase or decrease in capacity

resistance with varying loaded edge distance for both materials.

� The model best predicted at 7D loaded edge distance for single bolt configuration and

over predicted for all other configurations.

� A decrease in predicted C/T values was observed with an increase in loaded edge

distance which was due to increase in the test resistance values along with increase in

loaded edge distance.

� Predicted C/T values for single bolt were greater than two bolt connections.

6.2.6 Fracture Model Results Comparison

� The capacity resistance calculated by both models increased with increase in loaded edge

distances due to the loaded edge distances being a variable in both model equations and

hence had a direct effect on the predicted capacity values, where capacity values

103

predicted by the Van der Put model were greater than those predicted by the Jensen

model for similar set configurations.

� LVL-1 had greater predicted capacity resistance values then LVL-2 for the same set of

configuration for the models due to the greater Mode I fracture energy and tension

perpendicular to grain strength measured for LVL-1.

� Predicted capacity resistance values for the 1/2 inch bolts were greater than the

corresponding 3/8 inch bolt size configurations in every case due to the decreased loaded

edge distance, since the NDS spacing requirement used for connection testing, is a

function of dowel diameter “D” (AF & PA 2005).

� The Van der Put model over predicted capacity values for all connection test

configurations, but the Jensen model over predicted capacity values only for the LVL-1

single bolt connections at both bolts sizes.

� The C/T ratios for LVL-1 were greater than LVL-2 for comparable connection test sets,

due to greater calculated values obtained for LVL-1 due to greater Mode-I fracture

energy and tension perpendicular to grain strength of LVL-1.

� In general the no difference was found between average C/T ratio of LVL-1 and LVL-2

for Van der Put model. The average C/T ratio of LVL-1 was significantly greater than

LVL-2 for Jensen model due to the greater tension perpendicular to grain strength value

of LVL-1 than LVL-2, used for predicting the Jensen model values.

6.2.7 Comparison between TR-12 and Fracture Models

� In general average C/T ratios at capacity from Van der Put model were significantly

greater than both TR-12 and Jensen model, except for two bolt connections at 4D loaded

edge distances, where ANOVA detected no significant difference (exception 3/8 inch two

bolt connections for LVL-2 at 4D loaded edge distances).

� For both materials and bolt sizes the average C/T ratios for TR-12 model were

significantly greater than Jensen model except for single bolt 7D loaded edge

configurations for LVL-1.

� Van der Put model over predicted at capacity and the Jensen model over predicted for

single bolt connection and predicted well for two bolt connection with respect to loaded

104

edge distances. TR-12 model showed an accurate prediction at 7D loaded edge distances

for single bolt connections and over predicted for all other cases.

� In general, the Van der put and Jensen models showed consistency in prediction of

capacity values with respect to change in loaded edge distances and TR-12 showed

greater prediction of capacity values at 4D loaded edge compared to 7D loaded edge

distances.

� For fracture models, C/T ratios at capacity for single bolt were greater than for two bolt

connections at both loaded edge distances; where as an inverse trend was observed for the

TR-12 model.

6.3 Limitations

� All connection tests had steel side members, and so the expected yield mode was

crushing in the main member.

� All tests were performed for the same span: depth ratio which was 3:1.

� Only LVL from two manufacturers was used. Different materials like PSL, MSR, etc.

were not considered.

� Only two dowel diameters were considered, ½ inch and 3/8 inch.

� Only monotonic loading was applied for all the tests.

6.4 Future Work Recommendations

Investigation should be carried out including more than two loaded edge distances in order to

obtain a trend. Current research tested only two loaded edge distances and could not establish

a trend. It would be interesting to know if actually the fracture models predict consistently at

different loaded edge distances.

Investigation of connection configuration with expected yield mode of IIIs and IV (bending

of fastener) would help in verifying the observed failures of this research that included

splitting of main member along with crushing of main member or bending of the fastener.

Specifically it would be interesting to know whether these modes would be allowed to

develop with lower dowel diameter where mixed failure of splitting and dowel bending was

observed in this research.

105

For the NDS ASD design, allowable shear check is observed to control for most of the cases

and shows highly conservative values from our research. For single bolt connection at 4D

loaded edge distance the calculated shear values were over 500% greater than calculated

connection resistance and at 7D loaded edge distance the predicted shear values were over

18% greater than predicted by connection resistance. Work on verifying to approve or

disapprove if actually this high conservativeness is needed.

It would also be interesting to know how the models would predict with more number of

dowels in staggered and different arrangements. However, use of larger beam size would be

more practical approach for such an investigation as with 2x8 materials (our case),

arrangement with more number of bolts may be difficult to attain adhering to the criteria of

end, edge and spacing distance requirement from the NDS.

106

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ASTM E 399-90. 2005c. Standard Test Method for Plain-Strain Fracture Toughness of

Metallic Materials. American Society of Testing and Materials, West

Conshohocken, PA.

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ASTM D 5764-97a. 2005j. Standard Test Method for Evaluating Dowel-Bearing Strength

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Appendix A

111

Connection Test – Load v/s Slip Curves

Appendix A

112

Appendix A

113

Appendix A

114

Appendix A

115

Appendix A

116

Appendix A

117

Appendix B

118

Connection Tests

Single Bolt Connection Tests

NAME CRACK FAILURE 5% OFFSET YIELD CAPACITY STIFFNESS DUCTILITY

LENGTH MODE LOAD DISP LOAD DISP RATIO

inch lbs inch lbs inch lb/in

L1-1-1 10.50 S 2939 0.0598 3094 0.1325 84564 2.22

L1-1-2 5.63 S 2774 0.0689 2902 0.1148 54485 1.67

L1-1-3 13.88 S-Im 2534 0.0660 2937 0.1610 61596 2.44

L1-1-4 11.25 S 2779 0.0846 2825 0.1469 46632 1.74

L1-1-5 13.25 S-Im 2048 0.0638 2421 0.1917 52831 3.01

L1-1-6 12.38 S-Im 2417 0.0726 2659 0.2293 50717 3.16

L1-1-7 15.38 S-Im 2320 0.1317 2425 0.1740 21740 1.32

L1-1-8 13.25 S 2160 0.0698 2344 0.2049 48217 2.94

L1-1-9 11.50 S-Im 2437 0.0789 3022 0.2038 45219 2.58

L1-1-10 16.38 S 2218 0.0781 2456 0.1843 41765 2.36

AVERAGE 12.34 2463 0.0774 2708 0.1743 50776 2.34

STDEV 2.98 294 0.0205 281 0.0357 15831 0.62

COV 24.15% 11.92% 26.49% 10.39% 20.45% 31.18% 26.26%




L1-2-1 16.88 S-IIIs 2288 0.0683 2753 0.2517 46150 3.68

L1-2-2 21.13 S-IIIs 2091 0.0503 2412 0.2431 66351 4.84

L1-2-3 21.25 S-IIIs 1965 0.1064 2013 0.1933 22430 1.82

L1-2-4 24.25 S-IIIs 1943 0.0844 2190 0.2046 29580 2.42

L1-2-5 19.25 S-IIIs 1983 0.0656 2316 0.1832 42324 2.79

L1-2-6 15.25 S-IIIs 2133 0.0710 2355 0.2165 40814 3.05

L1-2-7 14.63 S-IIIs 2038 0.0542 2408 0.2032 57561 3.75

L1-2-8 16.13 S-IIIs 2123 0.0680 2540 0.2217 43079 3.26

L1-2-9 18.75 S-IIIs 2067 0.0742 2555 0.2034 37270 2.74

L1-2-10 13.00 S-IIIs 1991 0.1078 2368 0.2050 22356 1.90

AVERAGE 18.05 2062 0.0750 2391 0.2126 40791 3.03

STDEV 3.50 103 0.0194 203 0.0213 14087 0.91

COV 19.39% 5.01% 25.89% 8.50% 10.03% 34.53% 30.21%




L1-3-1 23.25 S-Im 2478 0.0727 4347 0.4837 51985 6.66

L1-3-2 22.5 S-Im 2332 0.0641 4469 0.4708 59688 7.35

L1-3-3 23.5 S-Im 2478 0.0642 4282 0.4680 63235 7.29

L1-3-4 25.375 S-Im 2471 0.0675 4518 0.4692 58072 6.95

L1-3-5 24.5 S-Im 2592 0.0729 4525 0.4731 54122 6.49

L1-3-6 17.325 S-Im 2659 0.0832 4205 0.3820 45654 4.59

L1-3-7 17.5 S-Im 3482 0.0613 4879 0.2386 95907 3.89

L1-3-8 24.5 S-Im 2982 0.0587 4567 0.3713 88673 6.33

L1-3-9 25.5 S-Im 2357 0.0655 4045 0.4782 58220 7.30

L1-3-10 17.5 S-Im 3171 0.0648 4968 0.3688 79645 5.69

AVERAGE 22.15 2700 0.0675 4481 0.4204 65520 6.25

STDEV 3.37 384 0.0071 285 0.0795 16716 1.19

COV 15.23% 14.24% 10.52% 6.36% 18.92% 25.51% 19.03%

Appendix B

119




L1-4-1 24.25 S-IIIs 1955 0.0806 3100 0.4561 31616 5.66

L1-4-2 21.63 S-IIIs 2013 0.1004 3212 0.3755 24645 3.74

L1-4-3 22.50 S-IIIs 2088 0.0669 3860 0.2961 43327 4.43

L1-4-4 25.38 S-IIIs 1990 0.0676 3253 0.3670 40737 5.43

L1-4-5 20.63 S-IIIs 2381 0.0650 3395 0.2700 51446 4.15

L1-4-6 17.63 S-IIIs 2066 0.0642 3801 0.2854 45456 4.45

L1-4-7 22.63 S-IIIs 2289 0.0553 4136 0.3183 62356 5.75

L1-4-8 20.33 S-IIIs 2418 0.0697 4146 0.2678 47471 3.84

L1-4-9 21.75 S-IIIs 1937 0.0897 3919 0.4300 27321 4.80

L1-4-10 19.50 S-IIIs 2049 0.0799 3941 0.3468 33453 4.34

AVERAGE 21.62 2119 0.0739 3676 0.3413 40783 4.66

STDEV 2.26 177 0.0136 397 0.0659 11698 0.73

COV 10.45% 8.38% 18.35% 10.79% 19.31% 28.68% 15.65%




L2-1-1 25.5 S 3795 0.1433 4278 0.3209 32075 2.24

L2-1-2 24.25 S 3413 0.0791 4998 0.3730 63098 4.72

L2-1-3 19.25 S-Im 3395 0.1201 4496 0.4720 35695 3.93

L2-1-4 23.875 S 3517 0.0625 4666 0.3202 93802 5.12

L2-1-5 25 S-Im 3335 0.0748 4650 0.4431 66973 5.92

L2-1-6 25.25 S-Im 3177 0.0542 4853 0.3690 108770 6.81

L2-1-7 12.875 S-Im 3696 0.0698 5072 0.2106 82587 3.02

L2-1-8 26 S-Im 3204 0.0847 4548 0.4015 53695 4.74

L2-1-9 26.375 S-Im 2659 0.0744 4277 0.3800 53805 5.11

L2-1-10 24.5 S-Im 3184 0.0729 4217 0.3590 66477 4.92

AVERAGE 23.29 3337 0.0836 4606 0.3649 65698 4.65

STDEV 4.16 317 0.0273 302 0.0723 24165 1.33

COV 17.88% 9.51% 32.65% 6.56% 19.81% 36.78% 28.49%

Appendix B

120

Two Bolt Connection Tests

NAME CRACK LENGTH

FAILURE

MODE

5% OFFSET

YIELD CAPACITY STIFFNESS DUCTILITY

TOP BOT TOP BOT LOAD DISP LOAD DISP RATIO

inch inch lbs inch lbs inch lb/in

L1-5-1 17.5 0 S - 4537 0.0947 4950 0.1854 64845 1.96

L1-5-2 15.875 0 S - 5200 0.1093 5402 0.1934 61707 1.77

L1-5-3 17.875 0 S - 4799 0.0793 5577 0.1662 88282 2.10

L1-5-4 14.75 0 S - 4915 0.0907 5006 0.1219 74681 1.34

L1-5-5 22.875 3.75 S-Im S-Im 4457 0.0802 5872 0.3266 78123 4.07

L1-5-6 15 3.125 S S 5443 0.1343 5666 0.2032 49816 1.51

L1-5-7 16.5 2 S S 4971 0.1020 5423 0.2008 67890 2.06

L1-5-8 17.375 1.25 S S 5250 0.1209 5254 0.1635 54633 1.35

L1-5-9 25.25 3.75 S S 5021 0.1264 5107 0.2431 49512 1.92

L1-5-10 16.125 0 S - 5114 0.0820 5971 0.2043 89412 2.49

AVERAGE 17.91 1.39 4971 0.1020 5423 0.2008 67890 2.06

STDEV 3.44 1.64 309 0.0200 351 0.0545 14597 0.79

COV 19.23% 118.19% 6.22% 19.66% 6.48% 27.14% 21.50% 38.55%

NAME CRACK LENGTH

FAILURE

MODE

5% OFFSET




L1-6-1 22.75 0 S-IIIs IIIs 3798 0.0843 3919 0.2262 57801 2.68

L1-6-2 25.5 0 S-IIIs IIIs 3483 0.0722 3572 0.2779 65143 3.85

L1-6-3 20.25 0 S-IIIs IIIs 3547 0.0780 3814 0.1969 59836 2.52

L1-6-4 17.25 9 S-IIIs S-IIIs 4068 0.1123 4152 0.2232 43238 1.99

L1-6-5 21.5 13.25 S-IIIs S-IIIs 4045 0.1031 4399 0.2119 47928 2.05

L1-6-6 21.75 0 S-IIIs IIIs 3148 0.0482 4084 0.2273 106797 4.71

L1-6-7 25 0 S-IIIs IIIs 3702 0.0668 4360 0.2958 77105 4.43

L1-6-8 21.75 0 S-IIIs IIIs 4231 0.1237 4339 0.2136 40265 1.73

L1-6-9 23.625 0 S-IIIs IIIs 3477 0.0509 4050 0.2198 1091774 4.31

L1-6-10 15.75 12.125 S-IIIs S-IIIs 4037 0.1057 4124 0.1942 46418 1.84

AVERAGE 21.51 3.44 3753 0.0845 4081 0.2287 163631 3.01

STDEV 3.11 5.63 343 0.0259 261 0.0329 326714 1.19

COV 14.46% 163.82% 9.13% 30.69% 6.38% 14.39% 199.67% 39.36%

NAME CRACK LENGTH

FAILURE

MODE

5% OFFSET




L1-7-1 10.5 3.5 S-Im S-Im 6322 0.1100 8208 0.2968 74313 2.70

L1-7-2 14.5 13.75 S-Im S-Im 7805 0.2773 8170 0.4321 30939 1.56

L1-7-3 25.625 0 S-Im Im 5199 0.0699 9111 0.6248 115922 8.94

L1-7-4 17.125 15.75 S-Im S-Im 5162 0.0718 6987 0.3150 110355 4.39

L1-7-5 20 17.25 S-Im S-Im 5451 0.1204 6658 0.3434 57134 2.85

L1-7-6 18.5 15 S-Im S-Im 6581 0.0671 8457 0.3139 156497 4.68

L1-7-7 22.25 14.75 S-Im S-Im 7003 0.1038 8598 0.3985 88890 3.84

L1-7-8 22.5 15.75 S-Im S-Im 5713 0.1202 7018 0.4814 60000 4.00

L1-7-9 26.875 0 S-Im Im 4791 0.0607 7105 0.3654 134262 6.02

L1-7-10 25.25 0 S-Im Im 6031 0.0786 8192 0.4117 112441 5.23

AVERAGE 20.31 9.58 6006 0.1080 7850 0.3983 94075 4.42

STDEV 5.25 7.61 937 0.0637 835 0.0989 38759 2.05

COV 25.83% 79.44% 15.60% 59.00% 10.64% 24.83% 41.20% 46.40%

Appendix B

121

NAME CRACK LENGTH

FAILURE

MODE

5% OFFSET




L1-8-1 23.75 2.5 S-IIIs S-IIIs 2436 0.0641325 5966 0.29298 53675 4.57

L1-8-2 26.25 1.5 S-IIIs S-IIIs 4346 0.066412 6021 0.3166375 91176 4.77

L1-8-3 26.5 11.25 S-IIIs S-IIIs 4803 0.0718425 6206 0.3706555 90458 5.16

L1-8-4 17.75 6.75 S-IIIs S-IIIs 4133 0.1165715 4745 0.2357505 42192 2.02

L1-8-5 22.75 3 S-IIIs S-IIIs 4537 0.087778 5988 0.249807 65726 2.85

L1-8-6 17.5 0 S-IIIs IIIs 4994 0.068139 7247 0.2293975 101123 3.37

L1-8-7 25.125 0 S-IIIs IIIs 4632 0.076545 5599 0.271911 80147 3.55

L1-8-8 23.375 6.5 S-IIIs S-IIIs 3980 0.0686865 6129 0.2991565 79692 4.36

L1-8-9 23 0 S-IIIs IIIs 5230 0.108327 6200 0.3120385 58385 2.88

L1-8-10 24.5 0 S-IIIs IIIs 5458 0.100897 6132 0.3151445 66441 3.12

AVERAGE 23.05 3.15 4455 0.0829 6023 0.2893 72901 3.66

STDEV 3.13 3.84 848 0.0192 615 0.0434 18720 1.01

COV 13.58% 121.88% 19.04% 23.21% 10.21% 15.01% 25.68% 27.47%

NAME CRACK LENGTH

FAILURE

MODE

5% OFFSET




L2-2-1 18.5 15 S S 4537 0.2071 4589 0.2756 24886 1.33

L2-2-2 25.5 15.75 S S 3773 0.1105 4625 0.2947 44127 2.67

L2-2-3 21.5 0 S - 4115 0.1008 4704 0.3259 54276 3.23

L2-2-4 14.75 1.75 S S 4104 0.0929 4223 0.1380 60415 1.49

L2-2-5 23.25 0 S - 4289 0.0963 4709 0.3248 60179 3.37

L2-2-6 24 0 S - 3942 0.1184 4568 0.2472 42216 2.09

L2-2-7 21.75 0 S - 3804 0.0876 4914 0.2671 60800 3.05

L2-2-8 25.75 14.75 S-Im S 4415 0.0957 5083 0.3142 62470 3.28

L2-2-9 15 7.625 S S 2517 0.0757 4496 0.2559 49689 3.38

L2-2-10 23.25 14.875 S S 4510 0.0908 4818 0.2528 68422 2.78

AVERAGE 21.33 6.98 4001 0.1076 4673 0.2696 52748 2.67

STDEV 3.99 7.35 589 0.0369 237 0.0549 12877 0.77

COV 18.69% 105.42% 14.72% 34.31% 5.06% 20.38% 24.41% 29.01%

NAME CRACK LENGTH

FAILURE

MODE

5% OFFSET




L2-3-1 22.5 19.25 S-IIIs S-IIIs 2376 0.1089 2588 0.2615 26349 2.40

L2-3-2 15.75 22.5 S-IIIs S-IIIs 3658 0.1025 3714 0.2942 43689 2.87

L2-3-3 22.5 0 S-IIIs IIIs 3436 0.0934 3559 0.2110 46058 2.26

L2-3-4 21.25 0 S-IIIs IIIs 3192 0.0458 3783 0.1831 118144 4.00

L2-3-5 22 2.25 S-IIIs S-IIIs 3365 0.0530 3723 0.2466 98263 4.65

L2-3-6 24.875 0 S-IIIs IIIs 3216 0.0625 3593 0.2453 73564 3.93

L2-3-7 26 0 S-IIIs IIIs 2848 0.0560 3339 0.2627 76271 4.69

L2-3-8 23.625 0 S-IIIs IIIs 3589 0.0645 4313 0.2466 78475 3.82

L2-3-9 26.325 0 S-IIIs IIIs 3369 0.0671 3724 0.3211 69387 4.78

L2-3-10 26 0 S-IIIs IIIs 2915 0.0520 3210 0.3295 87641 6.34

AVERAGE 23.08 4.40 3197 0.0706 3555 0.2602 71784 3.97

STDEV 3.16 8.74 388 0.0226 448 0.0455 27267 1.24

COV 13.70% 198.75% 12.15% 32.05% 12.61% 17.49% 37.98% 31.22%

Appendix B

122

NAME CRACK LENGTH

FAILURE

MODE

5% OFFSET




L2-4-1 13 15.25 S S 7357 0.1166 7680 0.2152 80315 1.85

L2-4-2 12.375 14.75 S S 2470 0.0801 6860 0.3549 44788 4.43

L2-4-3 15.5 15.5 S-Im S-Im 6214 0.1526 6559 0.2880 48714 1.89

L2-4-4 16.75 11.5 S S 5987 0.0831 7481 0.2461 103069 2.96

L2-4-5 22 15.125 S-Im S-Im 6549 0.1450 7477 0.3469 54574 2.39

L2-4-6 17 14.75 S-Im S-Im 6164 0.0911 7750 0.3725 93001 4.09

L2-4-7 18 14.5 S-Im S-Im 5453 0.0904 6675 0.2775 82934 3.07

L2-4-8 16.5 14.75 S S 6502 0.1105 7097 0.2390 76021 2.16

L2-4-9 16.25 15.25 S S 5978 0.1011 6525 0.2344 78566 2.32

L2-4-10 16.75 15 S S 7016 0.1766 7492 0.2780 46296 1.57

AVERAGE 16.41 14.64 5969 0.1147 7160 0.2853 70828 2.67

STDEV 2.65 1.14 1344 0.0329 475 0.0553 20784 0.96

COV 16.14% 7.81% 22.52% 28.66% 6.63% 19.39% 29.34% 35.93%

NAME CRACK LENGTH

FAILURE

MODE

5% OFFSET




L2-5-1 22.625 12.875 S-IIIs S-IIIs 3994 0.0737 5349 0.3248 72721 4.41

L2-5-2 22.875 9.75 S-IIIs S-IIIs 5475 0.1539 5786 0.2694 40485 1.75

L2-5-3 20.5 23.875 S-IIIs S-IIIs 4114 0.0836 4834 0.2917 63466 3.49

L2-5-4 24.25 13.5 S-IIIs S-IIIs 2496 0.0674 5472 0.4349 51361 6.46

L2-5-5 24.75 5.875 S-IIIs S-IIIs 5386 0.1458 5419 0.2869 42409 1.97

L2-5-6 23.875 13 S-IIIs S-IIIs 4506 0.1092 5261 0.3834 49789 3.51

L2-5-7 18.625 13.5 S-IIIs S-IIIs 3688 0.0626 5275 0.3077 84126 4.92

L2-5-8 26.25 1.75 S-IIIs S-IIIs 3880 0.1059 4956 0.4188 44503 3.95

L2-5-9 25.875 8.875 S-IIIs S-IIIs 4283 0.1123 5196 0.3651 45684 3.25

L2-5-10 24.5 7.275 S-IIIs IIIs 4385 0.0706 5533 0.3038 84527 4.30

AVERAGE 23.41 11.03 4221 0.0985 5308 0.3386 57907 3.80

STDEV 2.36 5.94 849 0.0326 276 0.0581 17088 1.37

COV 10.10% 53.87% 20.10% 33.06% 5.20% 17.17% 29.51% 36.15%

Appendix C

123

TR-12 5% Calculations

NAME DOWEL MAIN MEMBER SIDE MEMBER BOLT TR-12 CT RESUTLS CALC/TEST

DIA BEARING EMBEDMENT BEARING EMBEDMENT BENDING Pmin YIELD LOAD YIELD

LENGTH STRENGTH LENGTH/SIDE STRENGTH STRNGTH MODE MODE

in inch psi inch psi psi lbs lbs

D,Ds,Dm lm Fem ls Fes Fb

L1-1-1 0.5 1.705 4971 0.5 139200 86500 4237 Im 2939 1.44

L1-1-2 0.5 1.691 4360 0.5 139200 86500 3687 Im 2774 1.33

L1-1-3 0.5 1.773 3222 0.5 139200 86500 2856 Im 2534 1.13

L1-1-4 0.5 1.702 4155 0.5 139200 86500 3536 Im 2779 1.27

L1-1-5 0.5 1.731 3750 0.5 139200 86500 3247 Im 2048 1.59

L1-1-6 0.5 1.744 3402 0.5 139200 86500 2966 Im 2417 1.23

L1-1-7 0.5 1.761 3393 0.5 139200 86500 2987 Im 2320 1.29

L1-1-8 0.5 1.748 3915 0.5 139200 86500 3422 Im 2160 1.58

L1-1-9 0.5 1.740 3529 0.5 139200 86500 3071 Im 2437 1.26

L1-1-10 0.5 1.765 3342 0.5 139200 86500 2949 Im 2218 1.33

AVERAGE 0.50 1.736 3804 0.50 139200 86500 3296 2463 1.34

STDEV 0.00 0.028 555 0.00 0 0 432 294 0.15

COV 0.00% 1.63% 14.58% 0.00% 0.00% 0.00% 13.12% 11.92% 11.15%






L1-2-1 0.375 1.739 4253 0.5 139200 57320 2773 Im 2288 1.21

L1-2-2 0.375 1.728 4789 0.5 139200 57320 3103 Im 2091 1.48

L1-2-3 0.375 1.628 4362 0.5 139200 57320 2664 Im 1965 1.36

L1-2-4 0.375 1.683 4428 0.5 139200 57320 2795 Im 1943 1.44

L1-2-5 0.375 1.645 4365 0.5 139200 57320 2692 Im 1983 1.36

L1-2-6 0.375 1.790 4397 0.5 139200 57320 2951 Im 2133 1.38

L1-2-7 0.375 1.737 4482 0.5 139200 57320 2919 Im 2038 1.43

L1-2-8 0.375 1.740 4095 0.5 139200 57320 2672 Im 2123 1.26

L1-2-9 0.375 1.778 3804 0.5 139200 57320 2536 Im 2067 1.23

L1-2-10 0.375 1.786 3940 0.5 139200 57320 2639 Im 1991 1.33

AVERAGE 0.38 1.725 4292 0.50 139200 57320 2774 2062 1.35

STDEV 0.00 0.057 284 0.00 0 0 172 103 0.09

COV 0.00% 3.28% 6.61% 0.00% 0.00% 0.00% 6.19% 5.01% 6.86%

Appendix C

124






L1-3-1 0.5 1.763 3218 0.5 139200 86500 2836 Im 2478 1.14

L1-3-2 0.5 1.761 3134 0.5 139200 86500 2759 Im 2332 1.18

L1-3-3 0.5 1.747 3371 0.5 139200 86500 2944 Im 2478 1.19

L1-3-4 0.5 1.780 3575 0.5 139200 86500 3182 Im 2471 1.29

L1-3-5 0.5 1.809 3773 0.5 139200 86500 3412 Im 2592 1.32

L1-3-6 0.5 1.718 4767 0.5 139200 86500 4096 Im 2659 1.54

L1-3-7 0.5 1.723 4086 0.5 139200 86500 3520 Im 3482 1.01

L1-3-8 0.5 1.722 3819 0.5 139200 86500 3289 Im 2982 1.10

L1-3-9 0.5 1.729 3467 0.5 139200 86500 2997 Im 2357 1.27

L1-3-10 0.5 1.660 4594 0.5 139200 86500 3813 Im 3171 1.20

AVERAGE 0.50 1.741 3780 0.50 139200 86500 3285 2700 1.22

STDEV 0.00 0.041 555 0.00 0 0 434 384 0.14

COV 0.00% 2.34% 14.68% 0.00% 0.00% 0.00% 13.21% 14.24% 11.70%






L1-4-1 0.375 1.737 4706 0.5 139200 57320 3066 Im 1955 1.57

L1-4-2 0.375 1.745 4614 0.5 139200 57320 3019 Im 2013 1.50

L1-4-3 0.375 1.812 4464 0.5 139200 57320 3034 Im 2088 1.45

L1-4-4 0.375 1.743 3960 0.5 139200 57320 2589 Im 1990 1.30

L1-4-5 0.375 1.758 3894 0.5 139200 57320 2568 Im 2381 1.08

L1-4-6 0.375 1.754 4224 0.5 139200 57320 2778 Im 2066 1.34

L1-4-7 0.375 1.808 3827 0.5 139200 57320 2595 Im 2289 1.13

L1-4-8 0.375 1.751 5099 0.5 139200 57320 3348 Im 2418 1.38

L1-4-9 0.375 1.829 3792 0.5 139200 57320 2601 Im 1937 1.34

L1-4-10 0.375 1.811 4369 0.5 139200 57320 2967 Im 2049 1.45

AVERAGE 0.38 1.775 4295 0.50 139200 57320 2856 2119 1.36

STDEV 0.00 0.035 435 0.00 0 0 269 177 0.15

COV 0.00% 2.00% 10.12% 0.00% 0.00% 0.00% 9.42% 8.38% 11.38%

Appendix C

125






L1-5-1 0.5 1.775 3443 0.5 139200 86500 6113 Im 4537 1.35

L1-5-2 0.5 1.721 4021 0.5 139200 86500 6918 Im 5200 1.33

L1-5-3 0.5 1.783 3387 0.5 139200 86500 6039 Im 4799 1.26

L1-5-4 0.5 1.733 4283 0.5 139200 86500 7422 Im 4915 1.51

L1-5-5 0.5 1.770 3405 0.5 139200 86500 6026 Im 4457 1.35

L1-5-6 0.5 1.766 3446 0.5 139200 86500 6085 Im 5443 1.12

L1-5-7 0.5 1.772 3635 0.5 139200 86500 6441 Im 4971 1.30

L1-5-8 0.5 1.649 3963 0.5 139200 86500 6535 Im 5250 1.24

L1-5-9 0.5 1.637 3631 0.5 139200 86500 5942 Im 5021 1.18

L1-5-10 0.5 1.759 3130 0.5 139200 86500 5506 Im 5114 1.08

AVERAGE 0.50 1.736 3634 0.50 139200 86500 6303 4971 1.27

STDEV 0.00 0.053 352 0.00 0 0 548 309 0.13

COV 0.00% 3.06% 9.70% 0.00% 0.00% 0.00% 8.69% 6.22% 9.93%






L1-6-1 0.375 1.719 4513 0.5 139200 57320 5818 Im 3798 1.53

L1-6-2 0.375 1.757 4919 0.5 139200 57320 6480 Im 3483 1.86

L1-6-3 0.375 1.808 4236 0.5 139200 57320 5743 Im 3547 1.62

L1-6-4 0.375 1.807 4325 0.5 139200 57320 5861 Im 4068 1.44

L1-6-5 0.375 1.794 4117 0.5 139200 57320 5540 Im 4045 1.37

L1-6-6 0.375 1.817 4817 0.5 139200 57320 6565 Im 3148 2.09

L1-6-7 0.375 1.798 3736 0.5 139200 57320 5038 Im 3702 1.36

L1-6-8 0.375 1.804 4039 0.5 139200 57320 5463 Im 4231 1.29

L1-6-9 0.375 1.724 4669 0.5 139200 57320 6037 Im 3477 1.74

L1-6-10 0.375 1.726 4317 0.5 139200 57320 5588 Im 4037 1.38

AVERAGE 0.38 1.775 4369 0.50 139200 57320 5813 3753 1.57

STDEV 0.00 0.040 366 0.00 0 0 461 343 0.26

COV 0.00% 2.23% 8.39% 0.00% 0.00% 0.00% 7.94% 9.13% 16.39%

Appendix C

126






L1-7-1 0.5 1.780 3733 0.5 139200 86500 6647 Im 6322 1.05

L1-7-2 0.5 1.675 4126 0.5 139200 86500 6911 Im 7805 0.89

L1-7-3 0.5 1.702 5104 0.5 139200 86500 8688 Im 5199 1.67

L1-7-4 0.5 1.729 3428 0.5 139200 86500 5927 Im 5162 1.15

L1-7-5 0.5 1.674 3346 0.5 139200 86500 5600 Im 5451 1.03

L1-7-6 0.5 1.779 4242 0.5 139200 86500 7548 Im 6581 1.15

L1-7-7 0.5 1.710 3771 0.5 139200 86500 6448 Im 7003 0.92

L1-7-8 0.5 1.678 3641 0.5 139200 86500 6109 Im 5713 1.07

L1-7-9 0.5 1.716 3409 0.5 139200 86500 5851 Im 4791 1.22

L1-7-10 0.5 1.708 4167 0.5 139200 86500 7118 Im 6031 1.18

AVERAGE 0.50 1.715 3897 0.50 139200 86500 6685 6006 1.13

STDEV 0.00 0.039 534 0.00 0 0 933 937 0.22

COV 0.00% 2.26% 13.72% 0.00% 0.00% 0.00% 13.95% 15.60% 19.26%






L1-8-1 0.375 1.731 5488 0.5 139200 57320 7123 Im 2436 2.92

L1-8-2 0.375 1.712 5478 0.5 139200 57320 7033 Im 4346 1.62

L1-8-3 0.375 1.636 4444 0.5 139200 57320 5452 Im 4803 1.14

L1-8-4 0.375 1.678 4114 0.5 139200 57320 5176 Im 4133 1.25

L1-8-5 0.375 1.694 3839 0.5 139200 57320 4877 Im 4537 1.07

L1-8-6 0.375 1.702 4248 0.5 139200 57320 5423 Im 4994 1.09

L1-8-7 0.375 1.717 5684 0.5 139200 57320 7319 Im 4632 1.58

L1-8-8 0.375 1.805 5098 0.5 139200 57320 6902 Im 3980 1.73

L1-8-9 0.375 1.704 5959 0.5 139200 57320 7615 Im 5230 1.46

L1-8-10 0.375 1.707 5911 0.5 139200 57320 7566 Im 5458 1.39

AVERAGE 0.38 1.708 5026 0.50 139200 57320 6449 4455 1.52

STDEV 0.00 0.043 795 0.00 0 0 1080 848 0.54

COV 0.00% 2.50% 15.82% 0.00% 0.00% 0.00% 16.75% 19.04% 35.65%

Appendix C

127






L2-1-1 0.5 1.585 5536 0.5 139200 86500 4386 Im 3795 1.16

L2-1-2 0.5 1.560 5402 0.5 139200 86500 4213 Im 3413 1.23

L2-1-3 0.5 1.513 5354 0.5 139200 86500 4049 Im 3395 1.19

L2-1-4 0.5 1.522 5980 0.5 139200 86500 4549 Im 3517 1.29

L2-1-5 0.5 1.597 5660 0.5 139200 86500 4519 Im 3335 1.35

L2-1-6 0.5 1.594 4896 0.5 139200 86500 3901 Im 3177 1.23

L2-1-7 0.5 1.596 4966 0.5 139200 86500 3964 Im 3696 1.07

L2-1-8 0.5 1.591 5375 0.5 139200 86500 4275 Im 3204 1.33

L2-1-9 0.5 1.581 4153 0.5 139200 86500 3283 Im 2659 1.23

L2-1-10 0.5 1.534 5655 0.5 139200 86500 4338 Im 3184 1.36

AVERAGE 0.50 1.567 5298 0.50 139200 86500 4148 3337 1.25

STDEV 0.00 0.033 514 0.00 0 0 375 317 0.09

COV 0.00% 2.09% 9.71% 0.00% 0.00% 0.00% 9.04% 9.51% 7.43%






L2-2-1 0.5 1.573 4569 0.5 139200 86500 7188 Im 4537 1.58

L2-2-2 0.5 1.602 4169 0.5 139200 86500 6680 Im 3773 1.77

L2-2-3 0.5 1.590 5909 0.5 139200 86500 9393 Im 4115 2.28

L2-2-4 0.5 1.429 4363 0.5 139200 86500 6233 Im 4104 1.52

L2-2-5 0.5 1.579 4945 0.5 139200 86500 7810 Im 4289 1.82

L2-2-6 0.5 1.573 4582 0.5 139200 86500 7206 Im 3942 1.83

L2-2-7 0.5 1.546 4712 0.5 139200 86500 7283 Im 3804 1.91

L2-2-8 0.5 1.583 4892 0.5 139200 86500 7742 Im 4415 1.75

L2-2-9 0.5 1.611 5584 0.5 139200 86500 8997 Im 2517 3.57

L2-2-10 0.5 1.614 4550 0.5 139200 86500 7343 Im 4510 1.63

AVERAGE 0.50 1.570 4827 0.50 139200 86500 7587 4001 1.97

STDEV 0.00 0.054 540 0.00 0 0 968 589 0.60

COV 0.00% 3.41% 11.19% 0.00% 0.00% 0.00% 12.76% 14.72% 30.65%

Appendix C

128






L2-3-1 0.375 1.582 5175 0.5 139200 57320 6139 Im 2376 2.58

L2-3-2 0.375 1.607 4542 0.5 139200 57320 5475 Im 3658 1.50

L2-3-3 0.375 1.546 7281 0.5 139200 57320 8441 Im 3436 2.46

L2-3-4 0.375 1.570 7120 0.5 139200 57320 8384 Im 3192 2.63

L2-3-5 0.375 1.539 5643 0.5 139200 57320 6513 Im 3365 1.94

L2-3-6 0.375 1.525 5630 0.5 139200 57320 6439 Im 3216 2.00

L2-3-7 0.375 1.548 5554 0.5 139200 57320 6448 Im 2848 2.26

L2-3-8 0.375 1.585 5386 0.5 139200 57320 6403 Im 3589 1.78

L2-3-9 0.375 1.558 5487 0.5 139200 57320 6411 Im 3369 1.90

L2-3-10 0.375 1.548 5534 0.5 139200 57320 6425 Im 2915 2.20

AVERAGE 0.38 1.561 5735 0.50 139200 57320 6708 3197 2.13

STDEV 0.00 0.025 838 0.00 0 0 948 388 0.37

COV 0.00% 1.59% 14.61% 0.00% 0.00% 0.00% 14.14% 12.15% 17.25%






L2-4-1 0.5 1.595 5222 0.5 139200 86500 8329 Im 7357 1.13

L2-4-2 0.5 1.589 5525 0.5 139200 86500 8778 Im 2470 3.55

L2-4-3 0.5 1.551 4785 0.5 139200 86500 7419 Im 6214 1.19

L2-4-4 0.5 1.568 4872 0.5 139200 86500 7638 Im 5987 1.28

L2-4-5 0.5 1.531 4975 0.5 139200 86500 7618 Im 6549 1.16

L2-4-6 0.5 1.598 5076 0.5 139200 86500 8113 Im 6164 1.32

L2-4-7 0.5 1.508 4824 0.5 139200 86500 7273 Im 5453 1.33

L2-4-8 0.5 1.566 5751 0.5 139200 86500 9004 Im 6502 1.38

L2-4-9 0.5 1.505 5112 0.5 139200 86500 7693 Im 5978 1.29

L2-4-10 0.5 1.531 4819 0.5 139200 86500 7377 Im 7016 1.05

AVERAGE 0.50 1.554 5096 0.50 139200 86500 7924 5969 1.47

STDEV 0.00 0.035 324 0.00 0 0 606 1344 0.74

COV 0.00% 2.23% 6.35% 0.00% 0.00% 0.00% 7.64% 22.52% 50.35%

Appendix C

129






L2-5-1 0.375 1.572 7042 0.5 139200 57320 8304 Im 3994 2.08

L2-5-2 0.375 1.551 6293 0.5 139200 57320 7322 Im 5475 1.34

L2-5-3 0.375 1.522 6875 0.5 139200 57320 7845 Im 4114 1.91

L2-5-4 0.375 1.538 5501 0.5 139200 57320 6347 Im 2496 2.54

L2-5-5 0.375 1.586 8031 0.5 139200 57320 9554 Im 5386 1.77

L2-5-6 0.375 1.606 6078 0.5 139200 57320 7320 Im 4506 1.62

L2-5-7 0.375 1.552 5426 0.5 139200 57320 6316 Im 3688 1.71

L2-5-8 0.375 1.558 6450 0.5 139200 57320 7534 Im 3880 1.94

L2-5-9 0.375 1.578 6094 0.5 139200 57320 7211 Im 4283 1.68

L2-5-10 0.375 1.517 5343 0.5 139200 57320 6078 Im 4385 1.39

AVERAGE 0.38 1.558 6313 0.50 139200 57320 7383 4221 1.80

STDEV 0.00 0.028 837 0.00 0 0 1041 849 0.35

COV 0.00% 1.81% 13.26% 0.00% 0.00% 0.00% 14.10% 20.10% 19.42%

Appendix C

130

TR-12 CAPACITY RESULTS




in inch psi inch psi psi lbs lbs TOP BOTTOM


L1-1-1 0.5 1.705 6353 0.5 139200 104990 5415 Im 3094 S 1.75

L1-1-2 0.5 1.691 6665 0.5 139200 104990 5636 Im 2902 S 1.94

L1-1-3 0.5 1.773 4516 0.5 139200 104990 4003 Im 2937 S-Im 1.36

L1-1-4 0.5 1.702 6233 0.5 139200 104990 5304 Im 2825 S 1.88

L1-1-5 0.5 1.731 5289 0.5 139200 104990 4579 Im 2421 S-Im 1.89

L1-1-6 0.5 1.744 5616 0.5 139200 104990 4896 Im 2659 S-Im 1.84

L1-1-7 0.5 1.761 4113 0.5 139200 104990 3620 Im 2425 S-Im 1.49

L1-1-8 0.5 1.748 5014 0.5 139200 104990 4384 Im 2344 S 1.87

L1-1-9 0.5 1.740 6444 0.5 139200 104990 5607 Im 3022 S-Im 1.86

L1-1-10 0.5 1.765 4356 0.5 139200 104990 3844 Im 2456 S 1.57

AVERAGE 0.50 1.736 5460 0.50 139200 104990 4729 2708 1.74

STDEV 0.00 0.028 942 0.00 0 0 753 281 0.20

COV 0.00% 1.63% 17.26% 0.00% 0.00% 0.00% 15.92% 10.39% 11.40%






L1-2-1 0.375 1.739 6373 0.5 139200 84560 4156 Im 2753 S-IIIs 1.51

L1-2-2 0.375 1.728 6358 0.5 139200 84560 4120 Im 2412 S-IIIs 1.71

L1-2-3 0.375 1.628 5867 0.5 139200 84560 3582 Im 2013 S-IIIs 1.78

L1-2-4 0.375 1.683 6206 0.5 139200 84560 3918 Im 2190 S-IIIs 1.79

L1-2-5 0.375 1.645 6366 0.5 139200 84560 3926 Im 2316 S-IIIs 1.70

L1-2-6 0.375 1.790 5722 0.5 139200 84560 3840 Im 2355 S-IIIs 1.63

L1-2-7 0.375 1.737 6060 0.5 139200 84560 3947 Im 2408 S-IIIs 1.64

L1-2-8 0.375 1.740 5712 0.5 139200 84560 3727 Im 2540 S-IIIs 1.47

L1-2-9 0.375 1.778 5827 0.5 139200 84560 3884 Im 2555 S-IIIs 1.52

L1-2-10 0.375 1.786 5391 0.5 139200 84560 3610 Im 2368 S-IIIs 1.52

AVERAGE 0.38 1.725 5988 0.50 139200 84560 3871 2391 1.63

STDEV 0.00 0.057 338 0.00 0 0 191 203 0.12

COV 0.00% 3.28% 5.64% 0.00% 0.00% 0.00% 4.93% 8.50% 7.16%

Appendix C

131






L1-3-1 0.5 1.763 6506 0.5 139200 104990 5735 Im 4347 S-Im 1.32

L1-3-2 0.5 1.761 5867 0.5 139200 104990 5165 Im 4469 S-Im 1.16

L1-3-3 0.5 1.747 5685 0.5 139200 104990 4965 Im 4282 S-Im 1.16

L1-3-4 0.5 1.780 5403 0.5 139200 104990 4808 Im 4518 S-Im 1.06

L1-3-5 0.5 1.809 5732 0.5 139200 104990 5185 Im 4525 S-Im 1.15

L1-3-6 0.5 1.718 6022 0.5 139200 104990 5174 Im 4205 S-Im 1.23

L1-3-7 0.5 1.723 6344 0.5 139200 104990 5465 Im 4879 S-Im 1.12

L1-3-8 0.5 1.722 5161 0.5 139200 104990 4445 Im 4567 S-Im 0.97

L1-3-9 0.5 1.729 5437 0.5 139200 104990 4701 Im 4045 S-Im 1.16

L1-3-10 0.5 1.660 5860 0.5 139200 104990 4864 Im 4968 S-Im 0.98

AVERAGE 0.50 1.741 5802 0.50 139200 104990 5050 4481 1.13

STDEV 0.00 0.041 417 0.00 0 0 377 285 0.11

COV 0.00% 2.34% 7.20% 0.00% 0.00% 0.00% 7.46% 6.36% 9.34%






L1-4-1 0.375 1.737 6217 0.5 139200 84560 4050 Im 3100 S-IIIs 1.31

L1-4-2 0.375 1.745 6413 0.5 139200 84560 4196 Im 3212 S-IIIs 1.31

L1-4-3 0.375 1.812 6051 0.5 139200 84560 4113 Im 3860 S-IIIs 1.07

L1-4-4 0.375 1.743 4902 0.5 139200 84560 3205 Im 3253 S-IIIs 0.99

L1-4-5 0.375 1.758 4647 0.5 139200 84560 3064 Im 3395 S-IIIs 0.90

L1-4-6 0.375 1.754 4857 0.5 139200 84560 3194 Im 3801 S-IIIs 0.84

L1-4-7 0.375 1.808 4670 0.5 139200 84560 3167 Im 4136 S-IIIs 0.77

L1-4-8 0.375 1.751 6372 0.5 139200 84560 4185 Im 4146 S-IIIs 1.01

L1-4-9 0.375 1.829 5216 0.5 139200 84560 3577 Im 3919 S-IIIs 0.91

L1-4-10 0.375 1.811 5827 0.5 139200 84560 3957 Im 3941 S-IIIs 1.00

AVERAGE 0.38 1.775 5517 0.50 139200 84560 3671 3676 1.01

STDEV 0.00 0.035 729 0.00 0 0 476 397 0.18

COV 0.00% 2.00% 13.21% 0.00% 0.00% 0.00% 12.96% 10.79% 17.75%

Appendix C

132






L1-5-1 0.5 1.775 6309 0.5 139200 104990 11201 Im 4950 S - 2.26

L1-5-2 0.5 1.721 4600 0.5 139200 104990 7916 Im 5402 S - 1.47

L1-5-3 0.5 1.783 6246 0.5 139200 104990 11137 Im 5577 S - 2.00

L1-5-4 0.5 1.733 6770 0.5 139200 104990 11731 Im 5006 S - 2.34

L1-5-5 0.5 1.770 6138 0.5 139200 104990 10864 Im 5872 S-Im S-Im 1.85

L1-5-6 0.5 1.766 6919 0.5 139200 104990 12220 Im 5666 S S 2.16

L1-5-7 0.5 1.772 6968 0.5 139200 104990 12348 Im 5423 S S 2.28

L1-5-8 0.5 1.649 5902 0.5 139200 104990 9732 Im 5254 S S 1.85

L1-5-9 0.5 1.637 5128 0.5 139200 104990 8394 Im 5107 S S 1.64

L1-5-10 0.5 1.759 4060 0.5 139200 104990 7141 Im 5971 S - 1.20

AVERAGE 0.50 1.736 5904 0.50 139200 104990 10268 5423 1.90

STDEV 0.00 0.053 997 0.00 0 0 1867 351 0.38

COV 0.00% 3.06% 16.89% 0.00% 0.00% 0.00% 18.18% 6.48% 19.96%






L1-6-1 0.375 1.719 5559 0.5 139200 84560 7167 Im 3919 S-IIIs IIIs 1.83

L1-6-2 0.375 1.757 6401 0.5 139200 84560 8433 Im 3572 S-IIIs IIIs 2.36

L1-6-3 0.375 1.808 6153 0.5 139200 84560 8342 Im 3814 S-IIIs IIIs 2.19

L1-6-4 0.375 1.807 5698 0.5 139200 84560 7721 Im 4152 S-IIIs S-IIIs 1.86

L1-6-5 0.375 1.794 6121 0.5 139200 84560 8236 Im 4399 S-IIIs S-IIIs 1.87

L1-6-6 0.375 1.817 6448 0.5 139200 84560 8788 Im 4084 S-IIIs IIIs 2.15

L1-6-7 0.375 1.798 4762 0.5 139200 84560 6422 Im 4360 S-IIIs IIIs 1.47

L1-6-8 0.375 1.804 5282 0.5 139200 84560 7145 Im 4339 S-IIIs IIIs 1.65

L1-6-9 0.375 1.724 6033 0.5 139200 84560 7801 Im 4050 S-IIIs IIIs 1.93

L1-6-10 0.375 1.726 5961 0.5 139200 84560 7716 Im 4124 S-IIIs S-IIIs 1.87

AVERAGE 0.38 1.775 5842 0.50 139200 84560 7777 4081 1.92

STDEV 0.00 0.040 526 0.00 0 0 715 261 0.26

COV 0.00% 2.23% 9.00% 0.00% 0.00% 0.00% 9.19% 6.38% 13.59%

Appendix C

133






L1-7-1 0.5 1.780 4918 0.5 139200 104990 8755 Im 8208 S-Im S-Im 1.07

L1-7-2 0.5 1.675 4758 0.5 139200 104990 7968 Im 8170 S-Im S-Im 0.98

L1-7-3 0.5 1.702 5853 0.5 139200 104990 9963 Im 9111 S-Im Im 1.09

L1-7-4 0.5 1.729 4861 0.5 139200 104990 8403 Im 6987 S-Im S-Im 1.20

L1-7-5 0.5 1.674 5208 0.5 139200 104990 8716 Im 6658 S-Im S-Im 1.31

L1-7-6 0.5 1.779 6402 0.5 139200 104990 11390 Im 8457 S-Im S-Im 1.35

L1-7-7 0.5 1.710 5008 0.5 139200 104990 8563 Im 8598 S-Im S-Im 1.00

L1-7-8 0.5 1.678 5924 0.5 139200 104990 9939 Im 7018 S-Im S-Im 1.42

L1-7-9 0.5 1.716 4695 0.5 139200 104990 8057 Im 7105 S-Im Im 1.13

L1-7-10 0.5 1.708 5552 0.5 139200 104990 9483 Im 8192 S-Im Im 1.16

AVERAGE 0.50 1.715 5318 0.50 139200 104990 9124 7850 1.17

STDEV 0.00 0.039 583 0.00 0 0 1067 835 0.15

COV 0.00% 2.26% 10.97% 0.00% 0.00% 0.00% 11.69% 10.64% 12.69%






L1-8-1 0.375 1.731 5866 0.5 139200 84560 7614 Im 5966 S-IIIs S-IIIs 1.28

L1-8-2 0.375 1.712 5994 0.5 139200 84560 7695 Im 6021 S-IIIs S-IIIs 1.28

L1-8-3 0.375 1.636 5998 0.5 139200 84560 7359 Im 6206 S-IIIs S-IIIs 1.19

L1-8-4 0.375 1.678 6061 0.5 139200 84560 7625 Im 4745 S-IIIs S-IIIs 1.61

L1-8-5 0.375 1.694 4963 0.5 139200 84560 6306 Im 5988 S-IIIs S-IIIs 1.05

L1-8-6 0.375 1.702 5375 0.5 139200 84560 6861 Im 7247 S-IIIs IIIs 0.95

L1-8-7 0.375 1.717 7670 0.5 139200 84560 9877 Im 5599 S-IIIs IIIs 1.76

L1-8-8 0.375 1.805 7443 0.5 139200 84560 10078 Im 6129 S-IIIs S-IIIs 1.64

L1-8-9 0.375 1.704 6940 0.5 139200 84560 8869 Im 6200 S-IIIs IIIs 1.43

L1-8-10 0.375 1.707 6743 0.5 139200 84560 8631 Im 6132 S-IIIs IIIs 1.41

AVERAGE 0.38 1.708 6305 0.50 139200 84560 8091 6023 1.36

STDEV 0.00 0.043 873 0.00 0 0 1241 615 0.26

COV 0.00% 2.50% 13.85% 0.00% 0.00% 0.00% 15.34% 10.21% 19.33%

Appendix C

134






L2-1-1 0.5 1.585 7759 0.5 139200 104990 6147 Im 4278 S 1.44

L2-1-2 0.5 1.560 6290 0.5 139200 104990 4906 Im 4998 S 0.98

L2-1-3 0.5 1.513 7098 0.5 139200 104990 5368 Im 4496 S-Im 1.19

L2-1-4 0.5 1.522 7401 0.5 139200 104990 5630 Im 4666 S 1.21

L2-1-5 0.5 1.597 6895 0.5 139200 104990 5505 Im 4650 S-Im 1.18

L2-1-6 0.5 1.594 6571 0.5 139200 104990 5235 Im 4853 S-Im 1.08

L2-1-7 0.5 1.596 6735 0.5 139200 104990 5376 Im 5072 S-Im 1.06

L2-1-8 0.5 1.591 7677 0.5 139200 104990 6106 Im 4548 S-Im 1.34

L2-1-9 0.5 1.581 5341 0.5 139200 104990 4222 Im 4277 S-Im 0.99

L2-1-10 0.5 1.534 6790 0.5 139200 104990 5209 Im 4217 S-Im 1.24

AVERAGE 0.50 1.567 6856 0.50 139200 104990 5370 4606 1.17

STDEV 0.00 0.033 712 0.00 0 0 559 302 0.15

COV 0.00% 2.09% 10.39% 0.00% 0.00% 0.00% 10.40% 6.56% 12.64%






L2-2-1 0.5 1.573 6346 0.5 139200 104990 9984 Im 4589 S S 2.18

L2-2-2 0.5 1.602 5052 0.5 139200 104990 8094 Im 4625 S S 1.75

L2-2-3 0.5 1.590 6628 0.5 139200 104990 10535 Im 4704 S - 2.24

L2-2-4 0.5 1.429 6049 0.5 139200 104990 8643 Im 4223 S S 2.05

L2-2-5 0.5 1.579 5585 0.5 139200 104990 8822 Im 4709 S - 1.87

L2-2-6 0.5 1.573 5508 0.5 139200 104990 8663 Im 4568 S - 1.90

L2-2-7 0.5 1.546 5874 0.5 139200 104990 9079 Im 4914 S - 1.85

L2-2-8 0.5 1.583 6037 0.5 139200 104990 9555 Im 5083 S-Im S 1.88

L2-2-9 0.5 1.611 6254 0.5 139200 104990 10078 Im 4496 S S 2.24

L2-2-10 0.5 1.614 5275 0.5 139200 104990 8513 Im 4818 S S 1.77

AVERAGE 0.50 1.570 5861 0.50 139200 104990 9196 4673 1.97

STDEV 0.00 0.054 499 0.00 0 0 799 237 0.19

COV 0.00% 3.41% 8.52% 0.00% 0.00% 0.00% 8.69% 5.06% 9.59%

Appendix C

135






L2-3-1 0.375 1.582 5825 0.5 139200 84560 6910 Im 2588 S-IIIs S-IIIs 2.67

L2-3-2 0.375 1.607 6468 0.5 139200 84560 7796 Im 3714 S-IIIs S-IIIs 2.10

L2-3-3 0.375 1.546 9192 0.5 139200 84560 10656 Im 3559 S-IIIs IIIs 2.99

L2-3-4 0.375 1.570 8198 0.5 139200 84560 9653 Im 3783 S-IIIs IIIs 2.55

L2-3-5 0.375 1.539 6896 0.5 139200 84560 7959 Im 3723 S-IIIs S-IIIs 2.14

L2-3-6 0.375 1.525 7152 0.5 139200 84560 8181 Im 3593 S-IIIs IIIs 2.28

L2-3-7 0.375 1.548 5922 0.5 139200 84560 6875 Im 3339 S-IIIs IIIs 2.06

L2-3-8 0.375 1.585 7403 0.5 139200 84560 8800 Im 4313 S-IIIs IIIs 2.04

L2-3-9 0.375 1.558 7278 0.5 139200 84560 8503 Im 3724 S-IIIs IIIs 2.28

L2-3-10 0.375 1.548 6784 0.5 139200 84560 7876 Im 3210 S-IIIs IIIs 2.45

AVERAGE 0.38 1.561 7112 0.50 139200 84560 8321 3555 2.36

STDEV 0.00 0.025 1014 0.00 0 0 1164 448 0.31

COV 0.00% 1.59% 14.26% 0.00% 0.00% 0.00% 13.99% 12.61% 13.16%






L2-4-1 0.5 1.595 6678 0.5 139200 104990 10651 Im 7680 S S 1.39

L2-4-2 0.5 1.589 5819 0.5 139200 104990 9245 Im 6860 S S 1.35

L2-4-3 0.5 1.551 5469 0.5 139200 104990 8480 Im 6559 S-Im S-Im 1.29

L2-4-4 0.5 1.568 5901 0.5 139200 104990 9251 Im 7481 S S 1.24

L2-4-5 0.5 1.531 5840 0.5 139200 104990 8943 Im 7477 S-Im S-Im 1.20

L2-4-6 0.5 1.598 5828 0.5 139200 104990 9314 Im 7750 S-Im S-Im 1.20

L2-4-7 0.5 1.508 5929 0.5 139200 104990 8939 Im 6675 S-Im S-Im 1.34

L2-4-8 0.5 1.566 6393 0.5 139200 104990 10009 Im 7097 S S 1.41

L2-4-9 0.5 1.505 5704 0.5 139200 104990 8584 Im 6525 S S 1.32

L2-4-10 0.5 1.531 5813 0.5 139200 104990 8897 Im 7492 S S 1.19

AVERAGE 0.50 1.554 5937 0.50 139200 104990 9231 7160 1.29

STDEV 0.00 0.035 347 0.00 0 0 657 475 0.08

COV 0.00% 2.23% 5.84% 0.00% 0.00% 0.00% 7.12% 6.63% 6.33%

Appendix C

136






L2-5-1 0.375 1.572 8247 0.5 139200 84560 9726 Im 5349 S-IIIs S-IIIs 1.82

L2-5-2 0.375 1.551 6551 0.5 139200 84560 7622 Im 5786 S-IIIs S-IIIs 1.32

L2-5-3 0.375 1.522 8276 0.5 139200 84560 9444 Im 4834 S-IIIs S-IIIs 1.95

L2-5-4 0.375 1.538 7496 0.5 139200 84560 8648 Im 5472 S-IIIs S-IIIs 1.58

L2-5-5 0.375 1.586 8161 0.5 139200 84560 9709 Im 5419 S-IIIs S-IIIs 1.79

L2-5-6 0.375 1.606 6826 0.5 139200 84560 8221 Im 5261 S-IIIs S-IIIs 1.56

L2-5-7 0.375 1.552 7466 0.5 139200 84560 8691 Im 5275 S-IIIs S-IIIs 1.65

L2-5-8 0.375 1.558 8890 0.5 139200 84560 10385 Im 4956 S-IIIs S-IIIs 2.10

L2-5-9 0.375 1.578 8081 0.5 139200 84560 9562 Im 5196 S-IIIs S-IIIs 1.84

L2-5-10 0.375 1.517 6398 0.5 139200 84560 7279 Im 5533 S-IIIs IIIs 1.32

AVERAGE 0.38 1.558 7639 0.50 139200 84560 8929 5308 1.69

STDEV 0.00 0.028 833 0.00 0 0 1005 276 0.26

COV 0.00% 1.81% 10.90% 0.00% 0.00% 0.00% 11.26% 5.20% 15.16%

Appendix D

137

Fracture Model Results

NAME MAIN MEMBER

TEST

RESULT VANDERPUT MODEL JENSEN MODEL

WIDTH SHEAR MODE-I MOE TENSION CAPACITY CAPACITY CALC/TEST CAPACITY CALC/TEST

MOD ENERGY PERP RESISTANCE RESISTANCE RESISTANCE

inch psi lb/in psi psi lbs lbs lbs

L1-1-1 1.705 1.02E+05 7.84 2.39E+06 244 3094 6525 2.11 4052 1.31

L1-1-2 1.691 1.02E+05 7.48 2.39E+06 268 2902 6322 2.18 4053 1.40

L1-1-3 1.773 1.02E+05 7.27 2.39E+06 195 2937 6549 2.23 3840 1.31

L1-1-4 1.702 1.02E+05 7.83 2.39E+06 254 2825 6508 2.30 4086 1.45

L1-1-5 1.731 1.02E+05 7.45 2.39E+06 175 2421 6467 2.67 3658 1.51

L1-1-6 1.744 1.02E+05 8.19 2.39E+06 127 2659 6832 2.57 3402 1.28

L1-1-7 1.761 1.02E+05 8.02 2.39E+06 169 2425 6824 2.81 3769 1.55

L1-1-8 1.748 1.02E+05 8.48 2.39E+06 207 2344 6965 2.97 4067 1.74

L1-1-9 1.740 1.02E+05 7.58 2.39E+06 263 3022 6563 2.17 4167 1.38

L1-1-10 1.765 1.02E+05 7.99 2.39E+06 127 2456 6827 2.78 3421 1.39

AVERAGE 1.736 1.02E+05 7.81 2.39E+06 203 2708 6638 2.48 3851 1.43

STDEV 0.03 0.00 0.37 0.00 53 281 207 0.32 282 0.14

COV 1.63% 0.00% 4.76% 0.00% 26.34% 10.39% 3.12% 12.79% 7.31% 9.68%

NAME MAIN MEMBER

TEST





L1-2-1 1.739 1.02E+05 7.24 2.39E+06 328 2753 5299 1.92 3618 1.31

L1-2-2 1.728 1.02E+05 7.86 2.39E+06 234 2412 5483 2.27 3369 1.40

L1-2-3 1.628 1.02E+05 6.69 2.39E+06 188 2013 4773 2.37 2804 1.39

L1-2-4 1.683 1.02E+05 7.35 2.39E+06 164 2190 5172 2.36 2857 1.30

L1-2-5 1.645 1.02E+05 7.84 2.39E+06 232 2316 5218 2.25 3197 1.38

L1-2-6 1.790 1.02E+05 7.80 2.39E+06 232 2355 5666 2.41 3474 1.48

L1-2-7 1.737 1.02E+05 7.62 2.39E+06 232 2408 5433 2.26 3344 1.39

L1-2-8 1.740 1.02E+05 8.06 2.39E+06 232 2540 5597 2.20 3416 1.34

L1-2-9 1.778 1.02E+05 7.63 2.39E+06 227 2555 5567 2.18 3400 1.33

L1-2-10 1.786 1.02E+05 8.57 2.39E+06 183 2368 5926 2.50 3314 1.40

AVERAGE 1.725 1.02E+05 7.66 2.39E+06 225 2391 5413 2.27 3279 1.37

STDEV 0.06 0.00 0.51 0.00 45 203 318 0.16 260 0.05

COV 3.28% 0.00% 6.59% 0.00% 19.79% 8.50% 5.87% 6.93% 7.94% 3.69%

Appendix D

138

NAME MAIN MEMBER

TEST





L1-3-1 1.763 1.02E+05 7.78 2.39E+06 240 4347 10557 2.43 5916 1.36

L1-3-2 1.761 1.02E+05 6.88 2.39E+06 191 4469 9914 2.22 5323 1.19

L1-3-3 1.747 1.02E+05 7.51 2.39E+06 269 4282 10241 2.39 5938 1.39

L1-3-4 1.780 1.02E+05 6.83 2.39E+06 301 4518 9955 2.20 5969 1.32

L1-3-5 1.809 1.02E+05 7.62 2.39E+06 181 4525 10711 2.37 5600 1.24

L1-3-6 1.718 1.02E+05 7.59 2.39E+06 198 4205 10085 2.40 5441 1.29

L1-3-7 1.723 1.02E+05 7.73 2.39E+06 265 4879 10204 2.09 5901 1.21

L1-3-8 1.722 1.02E+05 6.97 2.39E+06 224 4567 9689 2.12 5452 1.19

L1-3-9 1.729 1.02E+05 8.46 2.39E+06 210 4045 10755 2.66 5790 1.43

L1-3-10 1.660 1.02E+05 8.07 2.39E+06 202 4968 10045 2.02 5404 1.09

AVERAGE 1.741 1.02E+05 7.54 2.39E+06 228 4481 10216 2.29 5673 1.27

STDEV 0.04 0.00 0.53 0.00 40 285 355 0.19 255 0.11

COV 2.34% 0.00% 7.00% 0.00% 17.33% 6.36% 3.48% 8.43% 4.50% 8.34%

NAME MAIN MEMBER

TEST





L1-4-1 1.737 1.02E+05 7.70 2.39E+06 199 3100 8049 2.60 4610 1.49

L1-4-2 1.745 1.02E+05 8.96 2.39E+06 223 3212 8728 2.72 5046 1.57

L1-4-3 1.812 1.02E+05 7.98 2.39E+06 222 3860 8552 2.22 5020 1.30

L1-4-4 1.743 1.02E+05 8.20 2.39E+06 213 3253 8343 2.56 4820 1.48

L1-4-5 1.758 1.02E+05 8.39 2.39E+06 272 3395 8514 2.51 5235 1.54

L1-4-6 1.754 1.02E+05 8.23 2.39E+06 215 3801 8410 2.21 4868 1.28

L1-4-7 1.808 1.02E+05 7.59 2.39E+06 212 4136 8334 2.02 4855 1.17

L1-4-8 1.751 1.02E+05 7.32 2.39E+06 238 4146 7912 1.91 4790 1.16

L1-4-9 1.829 1.02E+05 7.60 2.39E+06 247 3919 8425 2.15 5118 1.31

L1-4-10 1.811 1.02E+05 7.54 2.39E+06 231 3941 8333 2.11 4969 1.26

AVERAGE 1.775 1.02E+05 7.95 2.39E+06 227 3676 8360 2.30 4933 1.36

STDEV 0.04 0.00 0.50 0.00 21 397 236 0.28 181 0.15

COV 2.00% 0.00% 6.27% 0.00% 9.24% 10.79% 2.82% 11.97% 3.67% 11.20%

Appendix D

139

NAME MAIN MEMBER

TEST





L1-5-1 1.775 1.02E+05 7.77 2.39E+06 232 4950 10606 2.14 5907 1.19

L1-5-2 1.721 1.02E+05 7.71 2.39E+06 202 5402 10182 1.89 5508 1.02

L1-5-3 1.783 1.02E+05 7.66 2.39E+06 223 5577 10576 1.90 5845 1.05

L1-5-4 1.733 1.02E+05 8.41 2.39E+06 255 5006 10754 2.15 6078 1.21

L1-5-5 1.770 1.02E+05 7.25 2.39E+06 333 5872 10219 1.74 6197 1.06

L1-5-6 1.766 1.02E+05 7.06 2.39E+06 270 5666 10073 1.78 5864 1.03

L1-5-7 1.772 1.02E+05 7.23 2.39E+06 272 5423 10209 1.88 5952 1.10

L1-5-8 1.649 1.02E+05 7.13 2.39E+06 229 5254 9430 1.80 5290 1.01

L1-5-9 1.637 1.02E+05 7.01 2.39E+06 258 5107 9285 1.82 5366 1.05

L1-5-10 1.759 1.02E+05 7.39 2.39E+06 251 5971 10257 1.72 5850 0.98

AVERAGE 1.736 1.02E+05 7.46 2.39E+06 252 5423 10159 1.88 5786 1.07

STDEV 0.05 0.00 0.43 0.00 36 351 477 0.15 300 0.08

COV 3.06% 0.00% 5.80% 0.00% 14.21% 6.48% 4.69% 8.09% 5.18% 7.21%

NAME MAIN MEMBER

TEST





L1-6-1 1.719 1.02E+05 7.39 2.39E+06 233 3919 7823 2.00 4690 1.20

L1-6-2 1.757 1.02E+05 8.51 2.39E+06 233 3572 8538 2.39 5050 1.41

L1-6-3 1.808 1.02E+05 7.47 2.39E+06 244 3814 8280 2.17 5010 1.31

L1-6-4 1.807 1.02E+05 8.15 2.39E+06 290 4152 8639 2.08 5404 1.30

L1-6-5 1.794 1.02E+05 7.74 2.39E+06 231 4399 8340 1.90 4966 1.13

L1-6-6 1.817 1.02E+05 7.60 2.39E+06 245 4394 8375 1.91 5079 1.16

L1-6-7 1.798 1.02E+05 8.01 2.39E+06 265 4360 8507 1.95 5228 1.20

L1-6-8 1.804 1.02E+05 7.75 2.39E+06 283 4339 8391 1.93 5261 1.21

L1-6-9 1.724 1.02E+05 7.84 2.39E+06 230 4050 8042 1.99 4791 1.18

L1-6-10 1.726 1.02E+05 7.43 2.39E+06 274 4124 7845 1.90 4916 1.19

AVERAGE 1.775 1.02E+05 7.79 2.39E+06 253 4112 8278 2.02 5040 1.23

STDEV 0.04 0.00 0.35 0.00 23 279 284 0.16 217 0.09

COV 2.23% 0.00% 4.55% 0.00% 9.16% 6.78% 3.43% 7.73% 4.31% 7.05%

Appendix D

140

NAME MAIN MEMBER

TEST





L1-7-1 1.780 1.02E+05 7.04 2.39E+06 152 8208 15417 1.88 6408 0.78

L1-7-2 1.675 1.02E+05 7.41 2.39E+06 260 8170 14824 1.81 6976 0.85

L1-7-3 1.702 1.02E+05 7.15 2.39E+06 270 9111 14861 1.63 7042 0.77

L1-7-4 1.729 1.02E+05 8.52 2.39E+06 218 6987 16619 2.38 7319 1.05

L1-7-5 1.674 1.02E+05 7.32 2.39E+06 233 6658 14842 2.23 6780 1.02

L1-7-6 1.779 1.02E+05 7.75 2.39E+06 254 8457 16168 1.91 7510 0.89

L1-7-7 1.710 1.02E+05 7.51 2.39E+06 112 8598 15462 1.80 5746 0.67

L1-7-8 1.678 1.02E+05 6.86 2.39E+06 225 7018 14441 2.06 6582 0.94

L1-7-9 1.716 1.02E+05 7.78 2.39E+06 243 7105 15724 2.21 7190 1.01

L1-7-10 1.708 1.02E+05 7.32 2.39E+06 285 8192 15113 1.84 7204 0.88

AVERAGE 1.715 1.02E+05 7.46 2.39E+06 225 7850 15347 1.98 6876 0.89

STDEV 0.04 0.00 0.47 0.00 54 835 674 0.23 520 0.12

COV 2.26% 0.00% 6.29% 0.00% 23.93% 10.64% 4.39% 11.89% 7.56% 13.80%

NAME MAIN MEMBER

TEST





L1-8-1 1.731 1.02E+05 7.17 2.39E+06 223 5966 10529 1.76 5773 0.97

L1-8-2 1.712 1.02E+05 7.11 2.39E+06 214 6021 10384 1.72 5634 0.94

L1-8-3 1.636 1.02E+05 7.29 2.39E+06 263 6206 10061 1.62 5704 0.92

L1-8-4 1.678 1.02E+05 8.08 2.39E+06 260 4745 10909 2.30 6075 1.28

L1-8-5 1.694 1.02E+05 10.66 2.39E+06 209 5988 12709 2.12 6433 1.07

L1-8-6 1.702 1.02E+05 6.92 2.39E+06 240 7247 10314 1.42 5697 0.79

L1-8-7 1.717 1.02E+05 7.58 2.39E+06 286 5599 10784 1.93 6188 1.11

L1-8-8 1.805 1.02E+05 7.08 2.39E+06 234 6129 11011 1.80 6059 0.99

L1-8-9 1.704 1.02E+05 7.03 2.39E+06 278 6200 10316 1.66 5930 0.96

L1-8-10 1.707 1.02E+05 7.26 2.39E+06 245 6132 10491 1.71 5849 0.95

AVERAGE 1.708 1.02E+05 7.62 2.39E+06 245 6023 10751 1.81 5934 1.00

STDEV 0.04 0.00 1.12 0.00 26 615 748 0.25 254 0.13

COV 2.50% 0.00% 14.70% 0.00% 10.79% 10.21% 6.96% 14.02% 4.28% 13.24%

Appendix D

141

NAME MAIN MEMBER

TEST





L2-1-1 1.585 1.00E+05 7.96 2.40E+06 94 4278 9488 2.22 4012 0.94

L2-1-2 1.560 1.00E+05 6.20 2.40E+06 155 4998 8239 1.65 4274 0.86

L2-1-3 1.513 1.00E+05 5.80 2.40E+06 116 4496 7732 1.72 3715 0.83

L2-1-4 1.522 1.00E+05 5.80 2.40E+06 135 4666 7776 1.67 3913 0.84

L2-1-5 1.597 1.00E+05 6.58 2.40E+06 86 4650 8691 1.87 3692 0.79

L2-1-6 1.594 1.00E+05 6.22 2.40E+06 214 4853 8432 1.74 4754 0.98

L2-1-7 1.596 1.00E+05 6.10 2.40E+06 137 5072 8364 1.65 4194 0.83

L2-1-8 1.591 1.00E+05 6.36 2.40E+06 159 4548 8506 1.87 4433 0.97

L2-1-9 1.581 1.00E+05 6.92 2.40E+06 109 4277 8819 2.06 4029 0.94

L2-1-10 1.534 1.00E+05 6.42 2.40E+06 184 4217 8242 1.95 4461 1.06

AVERAGE 1.567 1.00E+05 6.44 2.40E+06 139 4606 8429 1.84 4148 0.90

STDEV 0.03 0.00 0.63 0.00 40 302 509 0.19 341 0.09

COV 2.09% 0.00% 9.85% 0.00% 28.96% 6.56% 6.04% 10.49% 8.23% 9.61%

NAME MAIN MEMBER

TEST





L2-2-1 1.573 1.00E+05 6.73 2.40E+06 101 4589 8646 1.88 3876 0.84

L2-2-2 1.602 1.00E+05 6.69 2.40E+06 200 4625 8779 1.90 4833 1.04

L2-2-3 1.590 1.00E+05 6.19 2.40E+06 148 4704 8391 1.78 4300 0.91

L2-2-4 1.429 1.00E+05 6.68 2.40E+06 129 4223 7825 1.85 3805 0.90

L2-2-5 1.579 1.00E+05 6.32 2.40E+06 187 4709 8418 1.79 4585 0.97

L2-2-6 1.573 1.00E+05 6.77 2.40E+06 145 4568 8687 1.90 4363 0.96

L2-2-7 1.546 1.00E+05 6.44 2.40E+06 145 4914 8326 1.69 4211 0.86

L2-2-8 1.583 1.00E+05 6.86 2.40E+06 146 5083 8795 1.73 4414 0.87

L2-2-9 1.611 1.00E+05 6.46 2.40E+06 142 4496 8678 1.93 4363 0.97

L2-2-10 1.614 1.00E+05 7.24 2.40E+06 162 4818 9207 1.91 4732 0.98

AVERAGE 1.570 1.00E+05 6.64 2.40E+06 150 4673 8575 1.84 4348 0.93

STDEV 0.05 0.00 0.30 0.00 28 237 365 0.08 330 0.06

COV 3.41% 0.00% 4.54% 0.00% 18.43% 5.06% 4.26% 4.50% 7.60% 6.94%

Appendix D

142

NAME MAIN MEMBER

TEST





L2-3-1 1.582 1.00E+05 6.80 2.40E+06 108 2588 6830 2.64 3301 1.28

L2-3-2 1.607 1.00E+05 6.50 2.40E+06 158 3714 6776 1.82 3741 1.01

L2-3-3 1.546 1.00E+05 6.58 2.40E+06 134 3559 6565 1.84 3432 0.96

L2-3-4 1.570 1.00E+05 6.38 2.40E+06 146 3783 6567 1.74 3543 0.94

L2-3-5 1.539 1.00E+05 6.05 2.40E+06 163 3723 6262 1.68 3526 0.95

L2-3-6 1.525 1.00E+05 5.87 2.40E+06 160 3593 6119 1.70 3438 0.96

L2-3-7 1.548 1.00E+05 6.36 2.40E+06 124 3339 6465 1.94 3310 0.99

L2-3-8 1.585 1.00E+05 6.42 2.40E+06 167 4313 6649 1.54 3731 0.87

L2-3-9 1.558 1.00E+05 6.44 2.40E+06 144 3724 6547 1.76 3506 0.94

L2-3-10 1.548 1.00E+05 6.22 2.40E+06 178 3210 6392 1.99 3671 1.14

AVERAGE 1.561 1.00E+05 6.36 2.40E+06 148 3555 6517 1.87 3520 1.00

STDEV 0.02 0.00 0.27 0.00 21 448 219 0.30 158 0.12

COV 1.59% 0.00% 4.17% 0.00% 14.34% 12.61% 3.35% 16.12% 4.48% 11.89%

NAME MAIN MEMBER

TEST





L2-4-1 1.595 1.00E+05 6.91 2.40E+06 144 7680 13732 1.79 5589 0.73

L2-4-2 1.589 1.00E+05 6.71 2.40E+06 109 6860 13456 1.96 5078 0.74

L2-4-3 1.551 1.00E+05 6.37 2.40E+06 118 6559 12781 1.95 4989 0.76

L2-4-4 1.568 1.00E+05 6.39 2.40E+06 230 7481 12961 1.73 5975 0.80

L2-4-5 1.531 1.00E+05 6.32 2.40E+06 144 7477 12577 1.68 5194 0.69

L2-4-6 1.598 1.00E+05 6.06 2.40E+06 162 7750 12860 1.66 5509 0.71

L2-4-7 1.508 1.00E+05 6.40 2.40E+06 73 6675 12464 1.87 4140 0.62

L2-4-8 1.566 1.00E+05 6.39 2.40E+06 84 7097 12943 1.82 4517 0.64

L2-4-9 1.505 1.00E+05 6.38 2.40E+06 144 6525 12427 1.90 5124 0.79

L2-4-10 1.531 1.00E+05 6.50 2.40E+06 114 7492 12763 1.70 4912 0.66

AVERAGE 1.554 1.00E+05 6.44 2.40E+06 132 7160 12896 1.81 5103 0.71

STDEV 0.03 0.00 0.23 0.00 45 475 416 0.11 526 0.06

COV 2.23% 0.00% 3.57% 0.00% 33.72% 6.63% 3.23% 6.16% 10.31% 8.61%

Appendix D

143

NAME MAIN MEMBER

TEST





L2-5-1 1.572 1.00E+05 6.52 2.40E+06 126 5349 9124 1.71 4317 0.81

L2-5-2 1.551 1.00E+05 6.19 2.40E+06 213 5786 8767 1.52 4819 0.83

L2-5-3 1.522 1.00E+05 6.10 2.40E+06 129 4834 8545 1.77 4107 0.85

L2-5-4 1.538 1.00E+05 6.32 2.40E+06 109 5472 8789 1.61 3981 0.73

L2-5-5 1.586 1.00E+05 6.25 2.40E+06 115 5419 9001 1.66 4161 0.77

L2-5-6 1.606 1.00E+05 6.54 2.40E+06 150 5261 9318 1.77 4640 0.88

L2-5-7 1.552 1.00E+05 6.76 2.40E+06 192 5275 9166 1.74 4860 0.92

L2-5-8 1.558 1.00E+05 6.55 2.40E+06 170 4956 9063 1.83 4669 0.94

L2-5-9 1.578 1.00E+05 6.57 2.40E+06 104 5196 9194 1.77 4080 0.79

L2-5-10 1.517 1.00E+05 6.43 2.40E+06 173 5533 8740 1.58 4538 0.82

AVERAGE 1.558 1.00E+05 6.42 2.40E+06 148 5308 8971 1.69 4417 0.83

STDEV 0.03 0.00 0.20 0.00 38 276 247 0.10 327 0.07

COV 1.81% 0.00% 3.16% 0.00% 25.42% 5.20% 2.76% 5.94% 7.40% 8.08%

Appendix E

144

Material Property Tests

Shear Modulus Test: ASTM D 198 Torsion

LVL-1

Specimen h b

Gage

Length Avg Slope G

(in) (in) (in) (in-lb/rad) (psi)

L1-1 7.343 1.713 32 39152 1.19E+05

L1-2 7.247 1.803 32 33851 9.07E+04

L1-3 7.262 1.647 32 23913 8.25E+04

L1-4 7.256 1.781 32 37675 1.04E+05

L1-5 7.353 1.717 32 41574 1.26E+05

L1-6 7.284 1.754 32 32705 9.41E+04

L1-7 7.267 1.813 32 38843 1.02E+05

L1-8 7.270 1.699 32 28039 8.86E+04

L1-9 7.262 1.826 32 34276 8.84E+04

L1-10 7.276 1.755 32 39980 1.15E+05

L1-11 7.376 1.718 32 35932 1.08E+05

L1-12 7.280 1.745 32 34311 1.00E+05

Avg 7.290 1.748 32.000 35021 1.02E+05

St Dev 0.041 0.050 0.000 4891 1.30E+04

COV 0.56% 2.87% 0.00% 13.96% 12.75%

LVL-2

Specimen h b

Gage

Length Avg Slope G

(in) (in) (in) (in-lb/rad) (psi)

L2-1 7.252 1.571 32 26288 1.04E+05

L2-2 7.273 1.626 32 25518 9.12E+04

L2-3 7.288 1.576 32 21552 8.39E+04

L2-4 7.264 1.529 32 25441 1.08E+05

L2-5 7.276 1.574 32 23132 9.06E+04

L2-6 7.278 1.581 32 23586 9.12E+04

L2-7 7.270 1.567 32 26779 1.06E+05

L2-8 7.231 1.576 32 27958 1.10E+05

L2-9 7.272 1.589 32 29252 1.12E+05

L2-10 7.258 1.532 32 23748 1.01E+05

L2-11 7.261 1.528 32 25321 1.08E+05

L2-12 7.263 1.578 32 24859 9.70E+04

Avg 7.265 1.569 32.000 25286 1.00E+05

St Dev 0.014 0.027 0.000 2045 8.84E+03

COV 0.19% 1.71% 0.00% 8.09% 8.82%

Appendix E

145

Shear Modulus Test Data: Torsion Torque - Rotation Curve

0

100

200

300

400

500

600

700

800

0 0.005 0.01 0.015 0.02

Tors

ion

(in

ch-l

b)

Rotation (rad)

LVL-1: L1-5 Trial 2

0

100

200

300

400

500

-0.005 0 0.005 0.01 0.015 0.02

To

rsio

n (

inch

-lb

)

Rotation (rad)

LVL-2: L2-1 Trial-1

Appendix E

146

Modulus of Elasticity: ASTM D 198 Three Point Bending Test

LVL-1

Specimen h b I L Avg Slope Ef G E

(in) (in) (in^4) (in) (lb/in) (psi) (psi) (psi)

L1-1 7.343 1.713 56.516 80 10727 2.02E+06 1.19E+05 2.44E+06

L1-2 7.247 1.803 57.188 80 10995 2.05E+06 9.07E+04 2.64E+06

L1-3 7.262 1.647 52.569 80 10194 2.07E+06 8.25E+04 2.75E+06

L1-4 7.256 1.781 56.692 80 9583 1.80E+06 1.04E+05 2.17E+06

L1-5 7.353 1.717 56.889 80 12001 2.25E+06 1.26E+05 2.75E+06

L1-6 7.284 1.754 56.499 80 9254 1.75E+06 9.41E+04 2.14E+06

L1-7 7.267 1.813 57.988 80 10676 1.96E+06 1.02E+05 2.43E+06

L1-8 7.270 1.699 54.386 80 8022 1.57E+06 8.86E+04 1.91E+06

L1-9 7.262 1.826 58.281 80 9318 1.71E+06 8.84E+04 2.11E+06

L1-10 7.276 1.755 56.326 80 9537 1.81E+06 1.15E+05 2.14E+06

L1-11 7.376 1.718 57.454 80 12051 2.24E+06 1.08E+05 2.84E+06

L1-12 7.280 1.745 56.106 80 9908 1.88E+06 1.00E+05 2.32E+06

Avg 7.290 1.748 56.408 80 10189 1.93E+06 1.02E+05 2.39E+06

St Dev 0.041 0.050 1.499 0 1123 2.01E+05 1.30E+04 2.90E+05

COV 0.56% 2.87% 2.66% 0.00% 11.02% 10.44% 12.75% 12.16%

LVL-2

Specimen h b I L Avg Slope Ef G E

(in) (in) (in^4) (in) (lb/in) (psi) (psi) (psi)

L2-1 7.252 1.571 49.947 80 8370 1.79E+06 1.04E+05 2.15E+06

L2-2 7.273 1.626 52.143 80 8639 1.77E+06 9.12E+04 2.19E+06

L2-3 7.288 1.576 50.852 80 9468 1.99E+06 8.39E+04 2.60E+06

L2-4 7.264 1.529 48.838 80 8740 1.91E+06 1.08E+05 2.31E+06

L2-5 7.276 1.574 50.517 80 9358 1.98E+06 9.06E+04 2.52E+06

L2-6 7.278 1.581 50.788 80 9573 2.01E+06 9.12E+04 2.57E+06

L2-7 7.270 1.567 50.164 80 8613 1.83E+06 1.06E+05 2.21E+06

L2-8 7.231 1.576 49.653 80 8580 1.84E+06 1.10E+05 2.21E+06

L2-9 7.272 1.589 50.924 80 9652 2.02E+06 1.12E+05 2.46E+06

L2-10 7.258 1.532 48.825 80 9706 2.12E+06 1.01E+05 2.68E+06

L2-11 7.261 1.528 48.745 80 9069 1.98E+06 1.08E+05 2.42E+06

L2-12 7.263 1.578 50.366 80 9196 1.95E+06 9.70E+04 2.43E+06

Avg 7.265 1.569 50.147 80 9080 1.93E+06 1.00E+05 2.40E+06

St Dev 0.015 0.028 1.018 0 475 1.06E+05 9.24E+03 1.80E+05

COV 0.20% 1.79% 2.03% 0.00% 5.24% 5.50% 9.21% 7.50%

Appendix E

147

Modulus of Elasticity: Load v/s Displacement Curve

0

300

600

900

1200

1500

1800

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14

Loa

d (

lbs)

Displacement (inch)

LVL-1: L1-5 Trial 2

0

300

600

900

1200

1500

1800

0 0.05 0.1 0.15 0.2

Load

(lb

s)

Displacement (inch)

LVL-2: L2-1 Trial-1

Appendix E

148

Bolt Bending Strength Test Data: ASTM F 1575-03 Cantilever Method

Set B1: ½” Bolt

Specimen

Capacity

(lbs)

5% Offset

Yield (lbs)

Capacity

Moment

(lbs-inch)

5% Offset Yield

Moment (lbs-inch)

Capacity

Strength

(psi)

5% Offset Yield

Strength (psi)

B1-1 1101 908 2202 1815 105695 87137

B1-2 1114 956 2227 1912 106896 91770

B1-3 1094 878 2187 1756 104997 84308

B1-4 1076 877 2152 1754 103284 84185

B1-5 1081 895 2162 1790 103759 85934

B1-6 1100 917 2199 1833 105563 87992

B1-7 1102 895 2204 1789 105775 85883

B1-8 1093 906 2185 1811 104881 86939

B1-9 1124 928 2248 1855 107925 89059

B1-10 1084 894 2168 1788 104051 85800

B1-11 1101 936 2202 1873 105693 89886

B1-12 1107 911 2214 1822 106291 87451

B1-13 1096 898 2192 1796 105237 86186

B1-14 1062 845 2123 1690 101905 81109

B1-15 1071 874 2143 1747 102860 83877

AVERAGE 1094 901 2187 1802 104987 86501

STDEV 17 27 33 55 1588 2631

COV 1.51% 3.04% 1.51% 3.04% 1.51% 3.04%

Bolt Bending Test: Load v/s Displacement Curve

0

500

1000

1500

2000

2500

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Lo

ad

(lb

s)

Displacement (inch)

Specimen B1-2

Appendix E

149

Set B2: 3/8” Bolt

Specimen

Capacity

(lbs)

5% Offset

Yield (lbs)

Capacity

Moment

(lbs-inch)

5% Offset

Yield Moment

(lbs-inch)

Capacity

Strength

(psi)

5% Offset Yield

Strength (psi)

B2-1 307 297 768 742 87353 84461

B2-2 289 206 721 514 82076 58530

B2-3 302 196 754 490 85774 55773

B2-4 278 179 694 449 78962 51052

B2-5 276 179 690 447 78518 50865

B2-6 320 239 799 597 90880 67930

B2-7 326 196 814 491 92663 55851

B2-8 302 189 754 473 85808 53765

B2-9 283 192 707 481 80421 54677

B2-10 300 194 751 486 85416 55246

B2-11 295 186 737 466 83803 52966

B2-12 296 191 739 478 84059 54337

B2-13 286 186 716 465 81448 52902

B2-14 292 191 729 479 82921 54447

B2-15 310 201 776 502 88303 57062

AVERAGE 297 202 743 504 84560 57324

STDEV 14 30 36 75 4102 8518

COV 4.85% 14.86% 4.85% 14.86% 4.85% 14.86%

Bolt Bending Test: Load v/s Displacement Curve

0

50

100

150

200

250

300

350

400

0 0.2 0.4 0.6 0.8 1

Lo

ad

(lb

s)

Displacement (inch)

Specimen B2-2

Appendix E

150

Dowel Embedment Test Data: ASTM D 5764-97a – Full Hole Specimens

LVL-1, ½” Bolt Dia.

Specimen

Thickness

(inch)

5% OFFSET YIELD CAPACITY

Load

(lbs)

Displacement

(inch)

Embedment

Strength (psi)

Load

(lbs)

Displacement

(inch)

Embedment

Strength (psi)

L1-1-1 1.7120 4255 0.129 4971 5438 0.500 6353

L1-1-2 1.6985 3703 0.116 4360 5660 0.498 6665

L1-1-3 1.7720 2855 0.139 3222 4002 0.430 4516

L1-1-4 1.7100 3552 0.120 4155 5329 0.438 6233

L1-1-5 1.7490 3280 0.125 3750 4625 0.465 5289

L1-1-6 1.7180 2922 0.138 3402 4824 0.492 5616

L1-1-7 1.7585 2983 0.118 3393 3616 0.269 4113

L1-1-8 1.7420 3410 0.119 3915 4367 0.363 5014

L1-1-9 1.7455 3080 0.115 3529 5624 0.489 6444

L1-1-10 1.7675 2953 0.116 3342 3849 0.262 4356

L1-3-1 1.7345 2791 0.113 3218 5643 0.500 6506

L1-3-2 1.7625 2762 0.113 3134 5170 0.500 5867

L1-3-3 1.7515 2952 0.118 3371 4979 0.479 5685

L1-3-4 1.7760 3175 0.117 3575 4798 0.482 5403

L1-3-5 1.8285 3449 0.118 3773 5240 0.460 5732

L1-3-6 1.7230 4107 0.120 4767 5188 0.373 6022

L1-3-7 1.7150 3504 0.110 4086 5440 0.467 6344

L1-3-8 1.7110 3267 0.117 3819 4415 0.409 5161

L1-3-9 1.7420 3020 0.120 3467 4736 0.486 5437

L1-3-10 1.6560 3804 0.122 4594 4852 0.500 5860

L1-5-1 1.7735 3053 0.117 3443 5595 0.500 6309

L1-5-2 1.7195 3457 0.126 4021 3955 0.290 4600

L1-5-3 1.8030 3053 0.115 3387 5630 0.500 6246

L1-5-4 1.7205 3684 0.122 4283 5824 0.485 6770

L1-5-5 1.7525 2983 0.112 3405 5379 0.464 6138

L1-5-6 1.7320 2984 0.109 3446 5992 0.476 6919

L1-5-7 1.7390 3160 0.119 3635 6058 0.497 6968

L1-5-8 1.6645 3298 0.111 3963 4912 0.415 5902

L1-5-9 1.6360 2970 0.117 3631 4195 0.340 5128

L1-5-10 1.7715 2773 0.113 3130 3596 0.255 4060

L1-7-1 1.7790 3321 0.119 3733 4374 0.270 4918

L1-7-2 1.6670 3439 0.114 4126 3966 0.231 4758

L1-7-3 1.7000 4338 0.151 5104 4975 0.269 5853

L1-7-4 1.7340 2972 0.121 3428 4214 0.300 4861

L1-7-5 1.6815 2813 0.127 3346 4378 0.374 5208

L1-7-6 1.7855 3787 0.134 4242 5715 0.403 6402

L1-7-7 1.7195 3242 0.125 3771 4305 0.500 5008

L1-7-8 1.6715 3043 0.132 3641 4951 0.500 5924

L1-7-9 1.6960 2891 0.125 3409 3981 0.436 4695

L1-7-10 1.7000 3542 0.111 4167 4719 0.426 5552

AVERAGE 1.7305 3266 0.121 3779 4863 0.420 5621

Appendix E

151

STDEV 0.0416 403 0.009 496 686 0.088 783

COV 2.40% 12.33% 7.31% 13.12% 14.11% 20.97% 13.92%

LVL-1, 3/8” Bolt Dia.

Specimen

Thickness

(inch)


Load

(lbs)

Displacement

(inch)

Embedment

Strength (psi)

Load

(lbs)

Displacement

(inch)

Embedment

Strength (psi)

L1-2-1 1.7405 2776 0.133 4253 4160 0.344 6373

L1-2-2 1.7200 3089 0.149 4789 4101 0.290 6358

L1-2-3 1.6415 2685 0.151 4362 3611 0.308 5867

L1-2-4 1.6665 2767 0.155 4428 3878 0.328 6206

L1-2-5 1.5805 2587 0.148 4365 3773 0.380 6366

L1-2-6 1.7810 2937 0.163 4397 3821 0.303 5722

L1-2-7 1.7560 2951 0.151 4482 3991 0.321 6060

L1-2-8 1.7405 2673 0.156 4095 3728 0.323 5712

L1-2-9 1.7655 2518 0.156 3804 3858 0.380 5827

L1-2-10 1.7660 2609 0.137 3940 3570 0.369 5391

L1-4-1 1.7555 3098 0.162 4706 4093 0.325 6217

L1-4-2 1.7400 3011 0.159 4614 4184 0.380 6413

L1-4-3 1.8070 3025 0.169 4464 4101 0.327 6051

L1-4-4 1.7345 2576 0.166 3960 3189 0.311 4902

L1-4-5 1.7600 2570 0.125 3894 3067 0.235 4647

L1-4-6 1.7555 2781 0.141 4224 3197 0.256 4857

L1-4-7 1.8130 2602 0.190 3827 3175 0.335 4670

L1-4-8 1.7480 3342 0.128 5099 4177 0.288 6372

L1-4-9 1.8305 2603 0.167 3792 3581 0.336 5216

L1-4-10 1.8125 2970 0.159 4369 3960 0.305 5827

L1-6-1 1.7105 2895 0.126 4513 3566 0.251 5559

L1-6-2 1.7100 3154 0.148 4919 4105 0.308 6401

L1-6-3 1.7840 2834 0.147 4236 4116 0.347 6153

L1-6-4 1.8055 2929 0.162 4325 3858 0.319 5698

L1-6-5 1.7895 2763 0.150 4117 4108 0.372 6121

L1-6-6 1.7955 3243 0.162 4817 4341 0.291 6448

L1-6-7 1.8055 2530 0.155 3736 3224 0.300 4762

L1-6-8 1.7980 2723 0.143 4039 3561 0.289 5282

L1-6-9 1.7175 3007 0.165 4669 3886 0.334 6033

L1-6-10 1.7120 2772 0.135 4317 3827 0.341 5961

L1-8-1 1.7185 3536 0.150 5488 3780 0.243 5866

L1-8-2 1.7295 3553 0.175 5478 3887 0.275 5994

L1-8-3 1.6825 2804 0.135 4444 3784 0.304 5998

L1-8-4 1.6810 2594 0.175 4114 3821 0.380 6061

L1-8-5 1.6695 2403 0.170 3839 3107 0.330 4963

L1-8-6 1.7055 2717 0.157 4248 3438 0.299 5375

L1-8-7 1.7035 3631 0.160 5684 4900 0.348 7670

L1-8-8 1.7955 3433 0.197 5098 5012 0.365 7443

L1-8-9 1.7075 3816 0.202 5959 4444 0.310 6940

Appendix E

152

L1-8-10 1.7175 3807 0.194 5911 4343 0.274 6743

AVERAGE 1.7413 2933 0.157 4495 3858 0.318 5913

STDEV 0.0532 366 0.018 580 438 0.038 686

COV 3.05% 12.48% 11.71% 12.90% 11.35% 12.01% 11.61%

LVL-2, ½” Bolt Dia.

Specimen

Thickness

(inch)


Load

(lbs)

Displacement

(inch)

Embedment

Strength (psi)

Load

(lbs)

Displacement

(inch)

Embedment

Strength (psi)

L2-1-1 1.5780 4368 0.151 5536 6122 0.332 7759

L2-1-2 1.5470 4178 0.148 5402 4865 0.253 6290

L2-1-3 1.4760 3951 0.130 5354 5238 0.307 7098

L2-1-4 1.5285 4570 0.157 5980 5656 0.282 7401

L2-1-5 1.5890 4497 0.148 5660 5478 0.323 6895

L2-1-6 1.5875 3886 0.144 4896 5215 0.357 6571

L2-1-7 1.6070 3990 0.145 4966 5412 0.305 6735

L2-1-8 1.6005 4301 0.152 5375 6143 0.329 7677

L2-1-9 1.5760 3273 0.122 4153 4209 0.286 5341

L2-1-10 1.5365 4345 0.144 5655 5216 0.271 6790

L2-2-1 1.5715 3590 0.161 4569 4986 0.450 6346

L2-2-2 1.5840 3302 0.138 4169 4001 0.311 5052

L2-2-3 1.6000 4727 0.144 5909 5302 0.269 6628

L2-2-4 1.5535 3389 0.150 4363 4699 0.327 6049

L2-2-5 1.5695 3880 0.146 4945 4383 0.317 5585

L2-2-6 1.5640 3583 0.134 4582 4308 0.277 5508

L2-2-7 1.5495 3651 0.150 4712 4551 0.419 5874

L2-2-8 1.5910 3891 0.156 4892 4803 0.299 6037

L2-2-9 1.6015 4471 0.200 5584 5008 0.315 6254

L2-2-10 1.6100 3663 0.152 4550 4247 0.313 5275

L2-4-1 1.5820 4131 0.142 5222 5283 0.256 6678

L2-4-2 1.5940 4403 0.161 5525 4637 0.245 5819

L2-4-3 1.5450 3696 0.174 4785 4225 0.301 5469

L2-4-4 1.5650 3812 0.150 4872 4617 0.301 5901

L2-4-5 1.5955 3969 0.135 4975 4659 0.290 5840

L2-4-6 1.5430 3916 0.133 5076 4496 0.281 5828

L2-4-7 1.5110 3644 0.138 4824 4479 0.482 5929

L2-4-8 1.5785 4539 0.151 5751 5046 0.303 6393

L2-4-9 1.5000 3834 0.132 5112 4278 0.315 5704

L2-4-10 1.5195 3661 0.146 4819 4416 0.395 5813

AVERAGE 1.5651 3970 0.148 5074 4866 0.317 6218

STDEV 0.0338 396 0.014 493 556 0.055 695

COV 2.16% 9.98% 9.75% 9.73% 11.42% 17.39% 11.18%

Appendix E

153

LVL-2, 3/8” Bolt Dia.

Specimen

Thickness

(inch)


Load

(lbs)

Displacement

(inch)

Embedment

Strength (psi)

Load

(lbs)

Displacement

(inch)

Embedment

Strength (psi)

L2-3-1 1.5840 3074 0.147 5175 3460 0.252 5825

L2-3-2 1.5910 2710 0.162 4542 3859 0.349 6468

L2-3-3 1.5545 4244 0.176 7281 5358 0.305 9192

L2-3-4 1.5725 4198 0.182 7120 4834 0.268 8198

L2-3-5 1.5205 3218 0.201 5643 3932 0.292 6896

L2-3-6 1.5235 3216 0.152 5630 4086 0.280 7152

L2-3-7 1.5410 3209 0.190 5554 3422 0.245 5922

L2-3-8 1.6050 3242 0.165 5386 4456 0.360 7403

L2-3-9 1.5815 3254 0.152 5487 4316 0.306 7278

L2-3-10 1.5240 3163 0.159 5534 3877 0.299 6784

L2-5-1 1.5580 4114 0.212 7042 4818 0.295 8247

L2-5-2 1.5550 3670 0.179 6293 3820 0.228 6551

L2-5-3 1.5345 3956 0.211 6875 4762 0.290 8276

L2-5-4 1.5190 3133 0.165 5501 4270 0.324 7496

L2-5-5 1.6335 4920 0.278 8031 4999 0.346 8161

L2-5-6 1.5905 3625 0.239 6078 4071 0.306 6826

L2-5-7 1.5555 3165 0.177 5426 4355 0.306 7466

L2-5-8 1.5375 3719 0.193 6450 5126 0.354 8890

L2-5-9 1.5795 3610 0.213 6094 4787 0.380 8081

L2-5-10 1.5190 3043 0.177 5343 3644 0.290 6398

AVERAGE 1.5590 3524 0.186 6024 4313 0.304 7375

STDEV 0.0325 537 0.032 867 565 0.040 943

COV 2.08% 15.24% 17.42% 14.40% 13.10% 13.08% 12.79%

Appendix E

154

Mode-I Fracture Energy Test Data: Compact Tension (CT) Specimens

LVL-1

Specimen Thickness (inch) Crack Length (inch) Max. Load (lbs) W (lb/inch) G (lb-in/in^2)

L1-1-1 1.717 3.650 211.67 30.82 7.84

L1-1-2 1.694 3.650 201.98 37.53 7.48

L1-1-3 1.756 3.650 216.37 50.81 7.27

L1-1-4 1.706 3.650 197.41 32.58 7.83

L1-1-5 1.727 3.650 199.41 42.97 7.45

L1-1-6 1.769 3.650 180.21 34.04 8.19

L1-1-7 1.741 3.650 173.03 35.80 8.02

L1-1-8 1.757 3.650 173.60 30.44 8.48

L1-1-9 1.758 3.650 215.72 39.43 7.58

L1-1-10 1.767 3.650 193.72 35.29 7.99

L1-2-1 1.751 3.650 239.07 44.45 7.24

L1-2-2 1.740 3.650 212.44 32.19 7.86

L1-2-3 1.599 3.650 211.81 48.67 6.69

L1-2-4 1.672 3.650 228.43 33.01 7.35

L1-2-5 1.638 3.650 176.73 30.90 7.84

L1-2-6 1.767 3.650 207.17 36.64 7.80

L1-2-7 1.730 3.650 208.25 36.98 7.62

L1-2-8 1.743 3.650 174.10 35.14 8.06

L1-2-9 1.794 3.650 205.52 45.18 7.63

L1-2-10 1.810 3.650 190.82 30.13 8.57

L1-3-1 1.757 3.650 216.75 34.26 7.78

L1-3-2 1.744 3.650 244.81 66.77 6.88

L1-3-3 1.716 3.650 208.62 38.00 7.51

L1-3-4 1.778 3.650 249.09 94.98 6.83

L1-3-5 1.788 3.650 228.17 38.93 7.62

L1-3-6 1.718 3.650 196.60 38.64 7.59

L1-3-7 1.707 3.650 181.51 36.94 7.73

L1-3-8 1.734 3.650 232.39 59.33 6.97

L1-3-9 1.710 3.650 172.07 28.37 8.46

L1-3-10 1.679 3.650 186.88 29.14 8.07

L1-4-1 1.729 3.650 219.18 32.94 7.70

L1-4-2 1.759 3.650 182.98 25.16 8.96

L1-4-3 1.829 3.650 210.15 38.32 7.98

L1-4-4 1.724 3.650 183.65 30.66 8.20

L1-4-5 1.750 3.650 166.10 31.88 8.39

L1-4-6 1.751 3.650 199.92 29.57 8.23

L1-4-7 1.793 3.650 202.68 47.04 7.59

L1-4-8 1.759 3.650 227.05 45.98 7.32

L1-4-9 1.834 3.650 242.88 42.04 7.60

L1-4-10 1.826 3.650 214.68 52.64 7.54

Appendix E

155

L1-5-1 1.746 3.650 213.43 34.16 7.77

L1-5-2 1.715 3.650 202.09 34.63 7.71

L1-5-3 1.781 3.650 191.94 45.37 7.66

L1-5-4 1.765 3.650 187.43 29.85 8.41

L1-5-5 1.775 3.650 230.90 51.65 7.25

L1-5-6 1.766 3.650 245.69 56.45 7.06

L1-5-7 1.781 3.650 246.10 48.45 7.23

L1-5-8 1.636 3.650 201.78 40.23 7.13

L1-5-9 1.659 3.650 194.31 49.74 7.01

L1-5-10 1.758 3.650 246.72 37.15 7.39

L1-6-1 1.710 3.650 223.60 37.27 7.39

L1-6-2 1.713 3.650 151.81 30.19 8.51

L1-6-3 1.817 3.650 242.75 45.01 7.47

L1-6-4 1.800 3.650 196.12 34.63 8.15

L1-6-5 1.801 3.650 209.57 41.75 7.74

L1-6-6 1.795 3.650 225.15 41.45 7.60

L1-6-7 1.815 3.650 187.65 40.49 8.01

L1-6-8 1.804 3.650 224.40 38.06 7.75

L1-6-9 1.716 3.650 185.91 35.09 7.84

L1-6-10 1.717 3.650 205.37 40.92 7.43

L1-7-1 1.662 3.650 233.83 39.05 7.04

L1-7-2 1.787 3.650 215.56 50.43 7.41

L1-7-3 1.717 3.650 233.96 43.81 7.15

L1-7-4 1.714 3.650 161.68 29.18 8.52

L1-7-5 1.680 3.650 215.00 37.58 7.32

L1-7-6 1.771 3.650 203.90 38.96 7.75

L1-7-7 1.704 3.650 194.65 39.47 7.51

L1-7-8 1.680 3.650 242.41 47.52 6.86

L1-7-9 1.699 3.650 187.20 34.55 7.78

L1-7-10 1.704 3.650 220.78 39.18 7.32

L1-8-1 1.732 3.650 226.28 47.75 7.17

L1-8-2 1.692 3.650 217.92 45.49 7.11

L1-8-3 1.704 3.650 220.43 40.00 7.29

L1-8-4 1.694 3.650 187.06 29.82 8.08

L1-8-5 1.701 3.650 171.35 17.91 10.66

L1-8-6 1.710 3.650 243.43 51.25 6.92

L1-8-7 1.710 3.650 200.96 37.19 7.58

L1-8-8 1.804 3.650 291.78 41.22 7.08

L1-8-9 1.689 3.650 228.49 45.16 7.03

L1-8-10 1.696 3.650 222.55 39.62 7.26

AVERAGE 1.738 3.650 208.94 39.90 7.66

STD 0.048 0.000 24.65 10.21 0.58

COV 2.76% 0.00% 11.80% 25.60% 7.56%

Appendix E

156

LVL-2

Specimen Thickness (inch) Crack Length (inch) Max. Load (lbs) W (lb/inch) G (lb-in/in^2)

L2-1-1 1.580 3.650 127.19 21.77 7.96

L2-1-2 1.543 3.650 194.57 41.10 6.20

L2-1-3 1.523 3.650 212.46 73.37 5.80

L2-1-4 1.510 3.650 229.75 44.65 5.80

L2-1-5 1.597 3.650 172.23 40.71 6.58

L2-1-6 1.629 3.650 227.31 53.77 6.22

L2-1-7 1.598 3.650 218.28 61.75 6.10

L2-1-8 1.603 3.650 193.02 47.70 6.36

L2-1-9 1.572 3.650 155.89 30.14 6.92

L2-1-10 1.537 3.650 171.04 37.11 6.42

L2-2-1 1.592 3.650 168.42 34.72 6.73

L2-2-2 1.599 3.650 176.85 34.83 6.69

L2-2-3 1.596 3.650 210.21 52.57 6.19

L2-2-4 1.545 3.650 174.97 29.07 6.68

L2-2-5 1.571 3.650 186.43 44.12 6.32

L2-2-6 1.571 3.650 159.08 33.01 6.77

L2-2-7 1.562 3.650 169.53 41.06 6.44

L2-2-8 1.605 3.650 164.22 33.58 6.86

L2-2-9 1.613 3.650 183.93 47.28 6.46

L2-2-10 1.620 3.650 155.50 28.21 7.24

L2-3-1 1.591 3.650 180.66 29.45 6.80

L2-3-2 1.617 3.650 180.40 47.14 6.50

L2-3-3 1.535 3.650 152.54 35.48 6.58

L2-3-4 1.570 3.650 196.12 36.32 6.38

L2-3-5 1.540 3.650 207.69 45.83 6.05

L2-3-6 1.525 3.650 219.55 52.08 5.87

L2-3-7 1.554 3.650 165.36 44.86 6.36

L2-3-8 1.570 3.650 176.94 41.34 6.42

L2-3-9 1.568 3.650 180.57 38.69 6.44

L2-3-10 1.547 3.650 191.57 42.33 6.22

L2-4-1 1.615 3.650 171.35 31.60 6.91

L2-4-2 1.598 3.650 183.84 32.04 6.71

L2-4-3 1.561 3.650 188.51 38.15 6.37

L2-4-4 1.599 3.650 197.60 42.22 6.39

L2-4-5 1.566 3.650 181.96 44.80 6.32

L2-4-6 1.520 3.650 195.80 44.25 6.06

L2-4-7 1.516 3.650 173.98 33.74 6.40

L2-4-8 1.547 3.650 171.74 39.83 6.39

L2-4-9 1.532 3.650 173.73 36.69 6.38

L2-4-10 1.547 3.650 163.07 37.49 6.50

L2-5-1 1.599 3.650 161.91 47.03 6.52

L2-5-2 1.565 3.650 195.55 48.41 6.19

L2-5-3 1.513 3.650 182.98 44.35 6.10

L2-5-4 1.547 3.650 177.80 41.70 6.32

Appendix E

157

L2-5-5 1.566 3.650 186.20 48.10 6.25

L2-5-6 1.638 3.650 195.11 43.93 6.54

L2-5-7 1.547 3.650 157.73 31.06 6.76

L2-5-8 1.561 3.650 171.03 35.66 6.55

L2-5-9 1.574 3.650 165.39 38.79 6.57

L2-5-10 1.515 3.650 169.61 33.53 6.43

AVERAGE 1.568 3.650 181.34 40.75 6.46

STD 0.033 0.000 20.29 8.94 0.36

COV 2.12% 0.00% 11.19% 21.93% 5.57%

Appendix E

158

Tension Perpendicular to Grain Strength Test Data: ASTM D 143

LVL-1

Specimen

Length

(inch)

Width

(inch)

Max Load

(lbs) Tensile Strength (psi)

L1-1-1 1.699 0.990 410.98 244

L1-1-2 1.684 0.984 444.41 268

L1-1-3 1.757 1.034 353.74 195

L1-1-4 1.700 1.007 434.40 254

L1-1-5 1.737 1.039 316.09 175

L1-1-6 1.735 1.012 222.37 127

L1-1-7 1.761 1.036 308.19 169

L1-1-8 1.739 1.032 370.92 207

L1-1-9 1.739 1.061 484.47 263

L1-1-10 1.762 1.069 239.43 127

L1-2-1 1.730 1.083 615.19 328

L1-2-2 1.717 1.020 408.94 234

L1-2-3 1.628 1.012 309.03 188

L1-2-4 1.659 1.022 277.35 164

L1-2-9 1.746 1.071 424.13 227

L1-2-10 1.807 1.017 336.34 183

L1-3-1 1.757 0.983 414.31 240

L1-3-2 1.748 0.976 325.27 191

L1-3-3 1.754 0.977 461.22 269

L1-3-4 1.776 0.962 514.50 301

L1-3-5 1.810 1.041 341.12 181

L1-3-6 1.714 1.045 354.41 198

L1-3-7 1.697 0.993 446.06 265

L1-3-8 1.708 0.988 378.24 224

L1-3-9 1.739 0.986 360.47 210

L1-3-10 1.650 0.997 332.12 202

L1-4-1 1.742 1.053 365.51 199

L1-4-2 1.724 1.105 423.78 223

L1-4-3 1.787 1.011 400.63 222

L1-4-4 1.737 1.024 378.55 213

L1-4-5 1.767 0.981 471.49 272

L1-4-6 1.753 0.987 371.46 215

L1-4-7 1.819 1.045 401.75 212

L1-4-8 1.763 1.005 421.86 238

L1-4-9 1.848 1.011 460.47 247

L1-4-10 1.801 1.037 431.67 231

L1-5-1 1.789 0.986 409.17 232

L1-5-2 1.733 1.017 355.13 202

L1-5-3 1.782 1.043 415.18 223

L1-5-4 1.714 1.080 471.65 255

L1-5-5 1.759 0.988 577.99 333

L1-5-6 1.729 1.018 474.66 270

Appendix E

159

L1-5-7 1.753 0.988 471.43 272

L1-5-8 1.659 0.973 368.98 229

L1-5-9 1.611 1.007 418.04 258

L1-5-10 1.769 1.015 450.95 251

L1-6-1 1.711 1.021 406.67 233

L1-6-2 1.700 1.023 405.73 233

L1-6-3 1.796 1.005 439.44 244

L1-6-4 1.801 1.012 528.39 290

L1-6-5 1.791 1.013 418.29 231

L1-6-6 1.822 0.977 436.74 245

L1-6-7 1.783 1.017 480.97 265

L1-6-8 1.813 1.041 534.15 283

L1-6-9 1.713 1.060 417.46 230

L1-6-10' 1.789 1.063 520.91 274

L1-7-1 1.788 1.005 273.57 152

L1-7-2 1.665 1.042 450.02 260

L1-7-3 1.685 1.016 462.68 270

L1-7-4 1.737 0.992 375.59 218

L1-7-5 1.686 1.017 398.55 233

L1-7-6 1.779 0.978 441.84 254

L1-7-7 1.716 1.057 202.92 112

L1-7-8 1.673 1.032 389.07 225

L1-7-9 1.705 0.982 407.35 243

L1-7-10 1.715 0.984 480.01 285

L1-8-1 1.735 0.996 385.08 223

L1-8-2 1.726 0.983 362.35 214

L1-8-3 1.674 1.015 446.18 263

L1-8-4 1.697 0.996 439.87 260

L1-8-5 1.671 1.018 354.88 209

L1-8-6 1.694 1.029 418.00 240

L1-8-7 1.727 1.025 505.89 286

L1-8-8 1.809 0.998 421.31 234

L1-8-9 1.702 0.983 465.60 278

L1-8-10 1.713 1.014 425.90 245

MEAN 1.737 1.016 409.47 232

STDEV 0.049 0.030 74.07 42

COV 2.79% 2.92% 18.09% 17.95%

Appendix E

160

LVL-2

Specimen

Length

(inch)

Width

(inch)

Max Load

(lbs) Tensile Strength (psi)

L2-1-1 1.572 0.995 146.37 94

L2-1-2 1.557 1.022 246.36 155

L2-1-3 1.490 1.003 173.99 116

L2-1-4 1.524 1.024 210.81 135

L2-1-5 1.588 1.021 139.80 86

L2-1-6 1.582 0.988 334.09 214

L2-1-7 1.600 1.015 221.97 137

L2-1-8 1.621 1.035 267.14 159

L2-1-9 1.561 1.018 172.59 109

L2-1-10 1.547 1.013 288.31 184

L2-2-1 1.578 1.040 165.92 101

L2-2-2 1.624 1.015 329.02 200

L2-2-3 1.598 1.106 262.23 148

L2-2-4 1.560 1.078 217.15 129

L2-2-5 1.585 1.000 296.01 187

L2-2-6 1.557 1.024 231.37 145

L2-2-7 1.533 1.041 231.18 145

L2-2-8 1.594 1.004 233.10 146

L2-2-9 1.606 1.008 229.07 142

L2-2-10 1.603 1.011 262.06 162

L2-3-1 1.599 0.995 172.45 108

L2-3-2 1.597 1.007 254.66 158

L2-3-3 1.559 1.003 210.13 134

L2-3-4 1.562 1.064 242.81 146

L2-3-5 1.519 1.040 258.13 163

L2-3-6 1.528 1.014 248.16 160

L2-3-7 1.535 1.009 192.39 124

L2-3-8 1.609 1.026 275.34 167

L2-3-10 1.540 1.064 291.25 178

L2-4-2 1.590 1.006 174.05 109

L2-4-3 1.554 1.020 187.26 118

L2-4-4 1.582 1.155 420.58 230

L2-4-6 1.537 1.018 253.56 162

L2-4-7 1.504 1.002 109.49 73

L2-4-8 1.515 0.982 124.56 84

L2-4-10 1.521 0.990 172.18 114

L2-5-1 1.572 1.005 199.67 126

L2-5-2 1.559 1.060 352.44 213

L2-5-3 1.528 0.993 195.62 129

L2-5-4 1.551 1.061 178.75 109

L2-5-5 1.613 1.018 188.07 115

L2-5-6 1.625 1.006 244.29 150

L2-5-7 1.558 1.044 312.72 192

L2-5-8 1.552 1.006 265.69 170

Appendix E

161

L2-5-9 1.520 1.003 158.99 104

L2-5-10 1.578 1.006 274.46 173

MEAN 1.565 1.023 230.79 144

STD 0.034 0.032 63.04 36

COV 2.17% 3.15% 27.31% 25.14%

Tension Perpendicular to Grain Strength Test: Load v/s Displacement Curves

0

100

200

300

400

500

0 0.01 0.02 0.03 0.04 0.05 0.06

Load

(lb

s)

Displacement (inch)

L-1-1-1

0

40

80

120

160

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14

Lo

ad

(lb

s)

Displacement (inch)

L2-1-1

Appendix E

162

Moisture Content and Specific Gravity Test Data: ASTM D 4442-92 and ASTM D 2395-93

LVL-1

Specimen Wet Weight (g) Dry weight (g) Volume (cm^3) Moisture Content (%) Specific Gravity

L1-1-1 19.40 17.48 27.40 10.98 0.64

L1-1-2 19.40 17.66 28.10 9.85 0.63

L1-1-3 17.50 15.95 28.40 9.72 0.56

L1-1-4 19.50 17.72 29.40 10.05 0.60

L1-1-5 18.40 16.79 28.90 9.59 0.58

L1-1-6 18.80 17.15 29.60 9.62 0.58

L1-1-7 18.40 16.85 29.20 9.20 0.58

L1-1-8 18.80 17.09 30.20 10.01 0.57

L1-1-9 18.40 16.76 29.30 9.79 0.57

L1-1-10 18.90 17.32 29.40 9.12 0.59

L1-2-1 21.10 19.21 29.70 9.84 0.65

L1-2-2 20.30 18.34 30.20 10.69 0.61

L1-2-3 17.50 16.01 25.90 9.31 0.62

L1-2-4 19.20 17.49 28.40 9.78 0.62

L1-2-5 18.00 16.31 28.10 10.36 0.58

L1-2-6 18.30 16.72 30.20 9.45 0.55

L1-2-7 19.30 17.62 30.00 9.53 0.59

L1-2-8 19.00 17.33 29.60 9.64 0.59

L1-2-9 16.90 15.47 30.30 9.24 0.51

L1-2-10 18.00 16.41 31.20 9.69 0.53

L1-3-1 18.10 16.45 29.40 10.03 0.56

L1-3-2 17.10 15.53 28.40 10.11 0.55

L1-3-3 18.50 16.77 28.40 10.32 0.59

L1-3-4 18.30 16.66 29.30 9.84 0.57

L1-3-5 18.40 16.73 30.60 9.98 0.55

L1-3-6 19.20 17.44 28.50 10.09 0.61

L1-3-7 19.80 17.94 28.90 10.37 0.62

L1-3-8 19.20 17.42 30.00 10.22 0.58

L1-3-9 17.80 16.24 29.70 9.61 0.55

L1-3-10 17.60 16.02 26.60 9.86 0.60

L1-4-1 17.80 16.19 29.10 9.94 0.56

L1-4-2 19.70 17.97 32.10 9.63 0.56

L1-4-3 18.10 16.43 29.90 10.16 0.55

L1-4-4 17.70 16.06 29.00 10.21 0.55

L1-4-5 20.10 18.25 30.30 10.14 0.60

L1-4-6 18.50 16.82 30.20 9.99 0.56

L1-4-7 18.60 16.90 29.80 10.06 0.57

L1-4-8 20.30 18.46 30.10 9.97 0.61

L1-4-9 19.90 18.16 31.10 9.58 0.58

L1-4-10 18.80 17.15 31.00 9.62 0.55

L1-5-1 18.40 16.75 30.70 9.85 0.55

L1-5-2 20.00 18.19 29.60 9.95 0.61

Appendix E

163

L1-5-3 19.20 17.44 31.10 10.09 0.56

L1-5-4 20.40 18.59 30.30 9.74 0.61

L1-5-5 18.60 16.87 30.00 10.25 0.56

L1-5-6 17.90 16.37 29.10 9.35 0.56

L1-5-7 19.50 17.79 31.90 9.61 0.56

L1-5-8 19.60 17.86 27.60 9.74 0.65

L1-5-9 18.20 16.59 28.30 9.70 0.59

L1-5-10 18.10 16.41 29.30 10.30 0.56

L1-6-1 20.10 18.28 30.90 9.96 0.59

L1-6-2 19.80 18.01 29.40 9.94 0.61

L1-6-3 17.90 16.30 31.20 9.82 0.52

L1-6-4 19.60 17.84 31.50 9.87 0.57

L1-6-5 18.30 16.51 28.40 10.84 0.58

L1-6-6 20.40 18.53 31.30 10.09 0.59

L1-6-7 19.50 17.67 31.60 10.36 0.56

L1-6-8 19.90 18.12 30.40 9.82 0.60

L1-6-9 19.80 17.94 28.60 10.37 0.63

L1-6-10 17.70 15.98 27.80 10.76 0.57

L1-7-1 19.55 17.86 29.70 9.46 0.60

L1-7-2 19.20 17.55 28.50 9.40 0.62

L1-7-3 18.03 16.41 27.80 9.87 0.59

L1-7-4 18.40 16.50 29.70 11.52 0.56

L1-7-5 16.49 15.09 28.10 9.28 0.54

L1-7-6 20.16 18.43 30.70 9.39 0.60

L1-7-7 18.54 16.96 29.90 9.32 0.57

L1-7-8 16.06 14.71 30.00 9.18 0.49

L1-7-9 17.59 16.10 29.60 9.25 0.54

L1-7-10 19.07 17.32 28.50 10.10 0.61

L1-8-1 20.20 18.43 29.40 9.60 0.63

L1-8-2 20.80 19.06 29.20 9.13 0.65

L1-8-3 20.00 18.20 29.50 9.89 0.62

L1-8-4 17.50 15.92 28.30 9.92 0.56

L1-8-5 19.00 17.35 29.40 9.51 0.59

L1-8-6 19.00 17.34 29.60 9.57 0.59

L1-8-7 21.70 19.84 29.80 9.38 0.67

L1-8-8 20.10 18.20 29.70 10.44 0.61

L1-8-9 20.30 18.36 29.30 10.57 0.63

L1-8-10 18.80 17.04 28.50 10.33 0.60

AVERAGE 18.90 17.20 29.50 9.88 0.58

STDEV 1.07 0.97 1.16 0.45 0.03

COV 5.68% 5.66% 3.94% 4.54% 5.72%

Appendix E

164

LVL-2

Specimen Wet Weight (g) Dry weight (g) Volume (cm^3) Moisture Content (%) Specific Gravity

L2-1-1 17.90 16.27 25.80 10.02 0.63

L2-1-2 18.90 17.13 25.50 10.33 0.67

L2-1-3 17.90 16.24 24.40 10.22 0.67

L2-1-4 19.00 17.41 25.10 9.13 0.69

L2-1-5 18.40 16.72 26.40 10.05 0.63

L2-1-6 18.10 16.41 26.90 10.30 0.61

L2-1-7 22.10 20.12 28.20 9.84 0.71

L2-1-8 19.70 17.95 26.60 9.75 0.67

L2-1-9 18.50 16.78 26.90 10.25 0.62

L2-1-10 19.30 17.59 27.00 9.72 0.65

L2-2-1 18.14 16.60 26.00 9.28 0.64

L2-2-2 19.62 17.89 28.40 9.67 0.63

L2-2-3 18.42 16.82 26.50 9.51 0.63

L2-2-4 19.34 17.61 26.20 9.82 0.67

L2-2-5 18.95 17.30 27.50 9.54 0.63

L2-2-6 18.24 16.61 26.70 9.81 0.62

L2-2-7 17.63 16.12 25.80 9.37 0.62

L2-2-8 18.30 16.68 26.40 9.71 0.63

L2-2-9 17.53 15.97 26.80 9.77 0.60

L2-2-10 18.66 16.60 26.60 12.41 0.62

L2-3-1 18.60 16.88 26.70 10.19 0.63

L2-3-2 18.90 17.13 27.40 10.33 0.63

L2-3-3 19.40 17.63 25.80 10.04 0.68

L2-3-4 17.40 15.83 25.60 9.92 0.62

L2-3-5 18.10 16.42 25.40 10.23 0.65

L2-3-6 17.60 15.97 24.10 10.21 0.66

L2-3-7 18.10 16.38 25.80 10.50 0.63

L2-3-8 17.90 16.22 26.30 10.36 0.62

L2-3-9 19.00 17.23 26.80 10.27 0.64

L2-3-10 17.70 16.07 26.30 10.14 0.61

L2-4-1 21.34 19.49 25.90 9.49 0.75

L2-4-2 19.85 18.14 27.30 9.43 0.66

L2-4-3 17.76 16.17 25.80 9.83 0.63

L2-4-4 17.25 15.69 25.90 9.94 0.61

L2-4-5 17.15 15.53 26.50 10.43 0.59

L2-4-6 16.93 15.42 25.40 9.79 0.61

L2-4-7 18.83 17.14 26.40 9.86 0.65

L2-4-8 18.25 16.64 26.90 9.68 0.62

L2-4-9 18.60 17.02 25.70 9.28 0.66

L2-4-10 18.51 16.90 25.60 9.53 0.66

L2-5-1 18.30 16.70 25.70 9.58 0.65

L2-5-2 18.57 16.95 25.80 9.56 0.66

L2-5-3 18.49 16.90 26.50 9.41 0.64

L2-5-4 18.80 17.19 26.60 9.37 0.65

Appendix E

165

L2-5-5 18.80 17.18 27.20 9.43 0.63

L2-5-6 20.02 18.26 27.50 9.64 0.66

L2-5-7 18.67 17.02 25.70 9.69 0.66

L2-5-8 18.46 16.83 26.20 9.69 0.64

L2-5-9 19.52 17.81 25.80 9.60 0.69

L2-5-10 18.40 16.82 26.70 9.39 0.63

AVERAGE 18.60 16.93 26.30 9.87 0.64

STDEV 0.95 0.89 0.82 0.51 0.03

COV 5.13% 5.24% 3.13% 5.13% 4.70%

Investigation of Single and Two Bolt Connections ...

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