7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 1/132
Com mission of the European Com munities
t e c h n i c a l s t e e l r e s e a r c h
Proper t ies and serv ice per formance
Measurement and interpretation of dynamicloads in bridges
Phase 3Fatigue behaviour of orthotropic steel decks
Synthesis Report
EUR 13378 EN
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 2/132
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 3/132
3
Commiss ion of the European Communit ies
t e c h n i c a l s t e e l r e s e a r c h
Properties and service performance
Measurement and interpretation of dynamicloads in bridges
Phase 3Fatigue behaviour of orthotopic steel decks
Edited by:
A. Bruls
Service 'Ponts et Charpentes'Université de Liège
Quai Banning 6B-4000 Liège
Contract No 7210-KD/119/201 /317/411 /609/807(1 July 1986 to 3 1 December 1988)
Synthesis report
Directorate-GeneralScience, Research and Development
1991
PARI [UROP Biblioth.
N.C. EUR 13378 E N
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 4/132
Published by theCOMMISSION OF THE EUROPEAN COMMUNITIES
Directorate-GeneralTelecommunications, Information Industries and Innovation
L-2920 Luxembourg
LEGAL NOTICENeither the Com mission of the European Communities nor any person acting
on behalf of the Commission is responsible for the use which might be made ofthe following information
Cataloguing data can be found at the end of this publication
Luxembourg: Office for Official Publications of the European Communities, 1991
ISBN 92-826-0532-9 Catalogue number: CD-NA-13378-EN-C
© ECSC-EEC-EAEC, Brussels • Luxem bourg, 1991
Printed in Belgium
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 5/132
SUMMARY.
This research, carried out with the financial help of the ECCS, concerned thefatigue strength of orthotropic steel decks of road bridges. It followed twophases that were concerned with the collection of traffic data and measurement
of stresses produced in bridges. Fatigue tests under constant and variableamplitude were carried out on stiffener-plate connections, stiffener-stiffenerconnections with U and V shapes, and stiffener cross-beam connections. Fromthe tests results and calculations some conclusions can be drawn which aredirectly usable in bridge design. However, some unexpected behaviour occuredand some connections need more investigation.
Résumé.
Cette recherche, réalisée avec l'aide financière de la CECA, concernait la
résistance à la fatigue des dalles orthotropes de ponts-routes. Elle faisaitsuite à deux phases qui se sont concentrées sur la collecte de donnéesrelatives aux charges du traffic et aux contraintes produites dans les ponts.Les essais de fatigue sous amplitude constante et variable ont été réaliséssur les assemblages raidisseur en U-tôles, les assemblagesraidisseur-raidissèur en U et en V, les assemblages raidisseurs-entretoise.Les résultats des essais et les calculs ont permis de tirer des conclusionsdirectement applicables au calcul des ponts-routes. Néanmoins descomportements imprévisibles s'étant manifestés, certains assemblages demandentdes investigations complémentaires.
Zusammenfassung.
Dieses Forschungsvorhaben wurde mit finanzieller Unterstützung der EGKSdurchgeführt und betraf das ErmUdungsverhalten orthotroper Platten vonStrassenbrüchen. Es folgte auf zwei Phasen, in denen hauptsachlich Daten überVerkehrslasten sowie Beanspruchungen von Brücken gesammelt wurden.Ermüdungsversuche unter konstanten und variablen Amplituden wurden fürfolgende Verbindungen durchgeführt : U-Längsverstelfung/Blech, U-undV-Längsversteifung, und Längsversteifung/Quertrager. Die Ergebnisse derVersuche und der Rechnungen erlaubten Schussfolgerungen, die direkt für dieAuslegung von Brücken anwendbar sind.
Aufgrund unerwarteter Verhaltenswesen der untersuchten Bauteile sind jedochzusatzliche Forschungen notwendig.
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 6/132
This report is a synthesis of the final reports performed
by each Laboratory that has participatedto the common research :
1. H.LEHRKE, Fraunhofer Institut fUr Betriebsfestigkeit, Bartningstrasse H7 _
6100 Darmstadt - Germany. [1]
2. A. BRULS, E. POLEUR, Service "Ponts.et Charpentes", Université de Liège,
6, quai Banning - 1)000 Liège - Belgique. [2]
3. A. BIGNONNET, I.R.S.I.D. 78105 Saint-Germain-en-Laye - France, and
J. CARRACILLI, B. JACOB, L.C.P.C., 58, Bd. Lefebvre - 75732 Paris - France.
C3]
k. S. CARAMELLI, P. CROCE, M. FR0LI, L. SANPAOLESI, Istituto di Scienza delle
Costruzioni, Università di Pisa, Via Diotisalvi, 2 - 56126 Pisa - Italy.
cu
5. H. KOLSTEIN, J. DE BACK, Stevin Laboratory, Universiteit van Delft, 2628 CN
Delft, Nederland. [5]
6. C. BEALES, Transport and Road Research Laboratory, Old Wokingham Road,
Crowthorne, United Kingdom [6].
Coordination : A. BRULS
IV
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 7/132
CONTENTS
Page
SUMMARY 111
RESUME 111
ZUSAMMENFASSUNG 111
1. INTRODU CTIO N 1
1.1 Orthotropic steel deck 1
1.2 Details tested 1
2 . METHODOLOGY OF FATIGU E PRE DICTION 5
2.1 Traffic loads and effects on bridg es 5
2.2 Classical life calculation 6
2.3 The fracture mechanic approach 9
3. CONN ECTION STIFF EN ER -P LATE 12
3.1 Types of connection 123.2 Stress determination 123.3 Fatigu e testing and results 153.4 Fatigu e life calculation 19
3.5 Crack propagation and lifetime calculations 203.6 Conclusion 224. CONNECTION STIFFE NER- STIFFE NER 404.1 Types of connections 404.2 Stress determination 404.3 Test results of the University of Pisa 424.4 Test results of the T.U. DELFT 454.5 Comparison with other research programs 514.6 Conclusions 51
5. CONNE CTION STIFFEN ER- CROS SBE AM 70
.5.1 Types of connection 70
5.2 Stress determination 705.3 Test results of TRR L 725.4 Test results of the T.U. Delft 755.5 Test results of the L.B.F . 77
5.6 Conclusions 79
6. OR THO TRO PI C DECK TO CRO SS BE AM CON NE CTIO N 106
7. APPLICATIONS 111
8. CONCLUS IO NS 112
BIBLIOGRAPHY 115
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 8/132
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 9/132
1. INTRODUCTION.
1.1. ORTHOTROPIC STEEL DECKS (Fig. 1.1).
Orthotropic steel decks are used in bridges with long spans and
in movable bridges in which dead weight has to be as low as possible.
The upper part of these decks is composed of a plate on which the
traffic runs. This plate is covered by a thin surfacing (7 to 12 mm) or an
asphalt surfacing (MO to 70 mm).
Longitudinal stiffeners are welded to the under part of the deck
plate, approximately 300 mm. apart, parallel to the direction of the
traffic lanes. They are usually closed sections with trapezoidal or "V"
shapes although open sections are sometimes used. The stiffeners transmitloads to crossbeams to which they are connected.
Crossbeams are normally spaced at 3 to 5 meters and are connected
to main girders or diaphrams.
Orthotropic steel decks are very sensitive to fatigue damage
because they are directly subjected to the actions of wheel loads which
give rise to stress ranges which are high compared to the dead load
stresses especially if the surfacing is thin.
In order to understand the fatigue behaviour of orthotropic steel
decks, the path of the traffic loads must be considered. Under the action
of wheels, the deck plate acts as a beam on elastic supports (the stiffener
webs). The elasticity of the supports decrases with the spacing of the
crossbeam. The web of the stiffeners are subjected to normal forces
(support reaction) and to bending moment if stiffeners have closed
sections.
Longitudinally the stiffeners are subjected to shear forces,
bending and torsion moments. The butt-welds connecting the longitudinal
stiffeners and the stiffener to crossbeam connection bear these effects.
1.2. Details tested.
This research concerns the study of the fatigue strength of
orthotropic decks with closed stiffeners. Bibliographical researches and
bridge examinations made during the two first phases have enabled us to
define details which are most sensitive to fatigue damage (Fig. 1.1).
- 1 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 10/132
* detail 1
* detail 2
* detail 3
*d e t a i l H
stiffener to deckplate connection,
stiffener to stiffener connection,
stiffener to crossbeam connection,
bolted connection crossbeam-orthotropic plate.
For each detail, the stress field was studied by calculation
and/or by measurement in the laboratory. Afterwards constant amplitude
fatigu e tests were carried out to define the S- N cu rv es. F inally specimens
were tested under variable amplitude load cycles simulating traffic
effects.
Distribution of the work between laboratories was as follows :
* detail 1 : stiffener to deck plate connection :
- University of Liège analysed local stresses with the help of
a finite band program and tested the connection under constant
and variable amplitude loading ;
- I R S I D carried ou t constant amplitu de tests on this connection
with a different welding procedure to that in the University of
Liège.
- L.C.P .C. developed and applied a fracture mechanics model.
* D etail 2 : stiffener to stiffener connection :
- Univ ersity of Pisa measured and calculated stresses on a full
size orthotropic deck ;
- University of Liège calculated stress histograms produced by
traffic loads using the results of the 1st and 2nd phases ;
- U niversity of P isa and T.U. Delft tested different designs of
this detail.
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 11/132
* Detail 3 : Stiffener to crossbeam connection.
- T.R.R.L. measured stresses in a full size orthotropic deck and
in an actual bridge ;
- L.B.F. calculated stresses in the web of the crossbeam withthe help of a finite element program.
- University of Liège calculated stress histograms produced by
traffic loads , using the results of the 1st and 2nd phases.
- T.R.R.L, T.U. Delft and L.B.F. tested different designs of this
detail.
* Detail 1J : bolted connection crossbeam-orthotropic plate.
- University of Liège tested this detail.
Using the traffic load data from the 1st and 2nd phases and the
fatigue data from the current research, it has been possible to make
some important conlusions about the fatigue behaviour of orthotropic
steel decks.
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 12/132
Longitudinal deck plate butt weld
Deck plate Transverse deck plate butt weld
/
de ta il ^ Longitudinal stiffener to deck plate Longitudinal stiffenerto crossbeam weld
Longi tud ina ls t i f f e n e r
de ta il (5 ) Longitudinal stiffener splice welds
Crossbeam to deck plate weld de tai l © st if fe ne r
to crossbeam connection(a l te rnat ive connect ions)
Crossbeam Diaphragm
Fi gu re 1 .1 Main welded connect ions in a typ ica l o r th ot op ic br idge deck
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 13/132
2. METHODOLOGY OF FATIGUE PREDICTION.
2.1. Traffic loads and effects on bridges.
During the first and second phase of the research [7][8],
measurements of traffic loads and stresses were carried out on 1 -4 highwaybridges. Different types of bridges and spans from 13 to 1000 m were
examined, most of them included orthotropic steel decks.
The traffic on these bridges was recorded and the number and types of
commercial vehicles identified and classified in a uniform scheme. Axle
loads, were measured by weighbridges, and axle spacings, separation between
vehicles and lateral wheel positions were also recorded. Additional sensors
simultaneously recorded the stresses produced in structural components like
main and cross girders, longitudinal stiffeners and deck plates.
The recorded stress histories were analysed using Level-crossing
and Rain-flow cycle counting methods. The resulting spectra were assessed
in terms of their fatigue damage potential with reference to constant
stress range fatigue design curves from existing or draft codes. Special
attention was paid to the possibility of calculating by means of finite
elements, and to the temperature dependent effect of the asphalt surfacing
in reducing the stresses.
Based on the experimental data a method of computer simulation oftraffic loads and stresses induced was developed and tested. It has proven
a suitable tool not only to reproduce the experimental data, but also to
derive more general results in that any uniform or hypothetical traffic
situation may be studied for the bridges investigated or for any components
of bridges described in terms of influence lines.
The main conclusions were :
1. The level of the measured axle and vehicle loads are much higher than
the allowed loads. Despite this observation, the measured stresses are
never higher than 90 N/mm2 ; which is not very much.
2. The number of vehicles is so high for some traffic, that exclusing the
vibration effect, the number of cycles produced during a life of 100a
years may reach 10° • which is very high.
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 14/132
3. The recording of a traffic flow comprising about 10 0 0 0 axles higher
than 10 kN will be sufficient to establish a spectrum reliably and to
allow a fatigue calculation.
Tw o types of v ehicle, the articulated 2- axled trailer with a 2- axled
semi trailer or with a 3 _axled semi trailer, have been found to produce
about 40 to 50 % of the total fatigue damage on Dutch bridges, although
they represent only 6 to 18 ? of the total number of commercial
vehicles.
i\ . As steel decks support hig h and frequent local stress ranges caused by
wheel loads, a main part of the work was concentrated on orthotropic
steel decks.
During the 2nd phase of the research, the most aggressive traffic was
recorded in the Netherlands on the Rheden bridge, where the frequency of
articulated lorries was hig hest. Therefore, in this work the Rheden traffic
was mainly considered for the determination (by simulation) of the stress
spectra used in fatigue tests. During the period of the third phase, new
measurements of traffic flow w ere made (independently of this w ork ) in
F rance, Germany and I taly. These data su g gest that the load of the vehicles
has not changed very much, but the number of articulated lorries and the
number of loaded lorries has increased. The results obtained by using the
R heden traffic are u sable, but the number of cycles are higher for somerecent traffic [9 ].
It is clear that the development of steel bridges needs the knowlegde of
the fatigue behaviour of the details of an orthotropic deck under variable
amplitude load and a high number of cycles ; thu s it needs the fatigu e
design curve for stress ranges beyond 2.10 cycles.
2. 2. Classical fatigue life calculation.
2 .2.1. Miner's rule.
During the life of a bridge, its components are subjected to
stress spectra induced by traffic. For the fatigue calculation it is
necessary to translate the actual stress spectra by a stress range
histogram.
Cycle counting methods such as Rain-flow or Range-Pair are commonly used to
produce stress range histrograms ; mean stress is not u sually considered.
A bridge is thus influenced by variable stress ranges, occuring randomly,
from the vehicle loads running on the bridge.
The fatigu e behav iour of the details are characterised by S- N
curves.
- 6 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 15/132
Fatigue damage is calculated using Miner's rule
D = Z (Ü L)A O l -0 N.
with n. = number of cycles in the stress range histrogram corresponding to
Aa. measured or calculated during a time t.
N, = number of cycles corresponding to Aa. in the S-N curve.
That is the number of cycles with a stress range of Aa.
producing failure.
If D < 1 : no failure
D - 1 : failure
The remaining fatigue life is — g — t.
In Eurocode the fatigue classification of a detail is defined by the value
Aa corresponding to N =2 .10 cycles.C c
Eurocode 3 considers SN curves with two slopes (Fig. 2.1) :
N.Aa3 = este = 5.106. Ao 3 i f Aa £ AaQ
5 6 5N.Aa = este - 5.10 . Aa if Ao^ > Aa i Aa T
D D L
N « » if Aa. > AaLi
where,
Aan corresponds to N =5.10 cycles ;u o g
AaTcorresponds to N = 1 0 cycles.Li L
The fatigue damage corresponds to
A aD n. . Aa5, " n. . Ao \
D E = Z U (_i L_) + E (_j__J_)Aa=Aa L 5.106.Aa 5
A a A o 5. 1 06. A a 3
1 D i D D
The lower part of the curve (m = 5) is important in bridges which
experience large numbers of low stress cycles.
- 7
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 16/132
2.2.2. Existing codes.
To design a structure, designers have to find information in codes
about actions, strengths and calculation methods. For the fatigue
assessment of bridges most of the codes propose the Miner's rule as thecalculation method. The action (traffic) is idealised by one or a set of
standard vehicles and the strengths are presented in the form of S-N
curves.
A. Action.
The action to consider in the fatigue assessment of bridges is the
action of traffic. During the first and second phases of the research,
measurements were made of traffic including the frequencies of vehicle
types and the level of loading of lorries. The traffic were compared to
try to detect local, regional or international influences.
It is not possible to define a spectrum taking all these influences into
account.
In existing codes actions are defined by one, two or three of the
following load models :
- one vehicle moving on an influence line allows the calculation of the
highest stress range (NBN 5 [10], BS 5^00 [11]) ;
- one vehicule moving on an influence line allows the calculation of the
stress range histogram (.La., n. ) by a cycle counting method (BS 5*100).
- a set of vehicles moving on the influence line allows the calculation of
the stress range histrogram (Aai, ni) by a cycle counting method (BS
5100).
B. Strength.
The different SN curves existing in codes are presented inFig. 2.1. The main remarks are :
- for constant amplitude loading, the S-N curves often have a slope of
-1/3 (m = 3) with an endurance limit. Previously the endurance limit
corresponded to N = 2.10 ,now it is associated with N - 5.10 (NBN)
[10], EC3 [12]) or 107(BS 5^00 [11], NEN [13]).
- for variable amplitude loading, the S-N curve is continued beyond the
endurance limit with a slope corresponding to m (NBN), m+2 (BS 5^00) or
2 m -1 (EC3).
o
- EC3 proposes a cut-off value at N - 10 below which the variable
amplitude loading does not produce any fatigue damage.- 8 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 17/132
- If the maximum value of the stress range A o m a x is below the endurance
limit, it is assumed that there is no fatigue damage (NBN).
C. Calculation.
A first verification, which is simple and conservative, is to
calculate the maximum stress range for the detail under the load model.
This value is compared with the endurance limit (NBN 5) or with charts
of limiting stress which vary according to the bridge span and detail
class (BS 5^00). The calculated stress range must be below the limiting
stress for the detail to be acceptable by this method.
The second verification is more precise. It involves a fatigue
damage calculation on the basis of the (Ao, n ) histogram defined by ii i the load model, using the Miner's rule.
2.3. The fracture mechanic approach.
The only method suitable for bridge design requires a Miner's
calculation, but the crack growth evaluation in an existing bridge
needs a fracture mechanic approach.
The classical Miner's calculation is very simple and does not take
into account the changes in the structure when a crack is propagating, or the mean stress level onto which the stress variations are
superimposed. Hence this model is very sensitive to the choice of the
S-N curves. For road bridges in which the stress variations are
generally much smaller than the permanent stresses, the computed
lifetimes are highly dependent on the high endurance end of the S-N
curves.
In the fracture mechanic approach, the crack propagation is
computed for each stress cycle, taking into account the present state
of the structure and hence the time history of the stress variations.
There are numerous laws describing this evolution ; the Paris one has
been chosen because of its simplicity and its ability to describe the
crack propagation in this type of structure. The crack propagation
speed is written as :
da m — — ■ c ÅK t where c and m are parameters depending on the
material and AK the stress intensity factor, depending on the stress range and on the local
geometry of the detail.
- 9 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 18/132
In order to account for a threshold, under which no crack may be propaged,
the Paris law is modified as
da ra'
_ = c' (AK - AK )dN s
The threshold plays a similar rule than the classical fatigue limit.
If the stress are both positive and negative, only tension is considered
for the crack propagation. But in the real bridges, it is generally assumed
that the residual stresses induce high forces, and the whole stress
variation are considered.
The crack propagation time is obtained by integrating this formula from the
initial crack length a to its .length a at the failure. The number ofo rstress cycles involved is :
1 ar m'N = N + _ ! ƒ (AK - AK ) da
C' a
O
where N is the number of cycles for the crack initiation. The failure
criteria adopted here is : a 0.5e, if e is the plate thickness ; it
corresponds to the loss of rigidity of the structure. The problem is then
to compute the AK values.
The cracked beam theory shows that AK may be generally written as :
AK = /la.Ao.f(a), where f(a) is a function of the structure geometry and
Aa is the stress range in the uncracked section studied.
For the orthotropic deck stiffener-plate connections, the following formula
may be adopted :
AK = /HaCA F + 2a_ A, F + _* 1 A„ F„ + ^ ì L A F + Ü _ A„ F„]o o f 1 1 2 2 2 3 í 3 3 8 ^ ^
where the F. are amplification factors depending on the crack geometry but
independent on the loading case. The A. are the coefficients of the
smoothing polynominal of the stress diagram.
This model has been applied by the LCPC to the stiffener-plate connection
behaviour in the chapter 3.
10
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 19/132
s.ioV
BS5¿00
•-N(log)
Ao. (log)
N(log)
NEN 2063
Ao (log)
AOc AOn .
AOL
,
^"""""^IT
2.1
i
"■ "■ "■»« ̂
0 * S.1
■ " ^ « « ^
2m-1
0 * 1
cut-off
o'
E C 3
AT 4 (log)
cut-off
2.10' S.V* 10*
EC 3
-Nllog)
Figure 2.1 : S-N curves
11 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 20/132
3. CONNECTION STIFFENER-PLATE.
3.1. Types of connection.
3.1.1. General considerations.
The main parts of the stiffener-deck plate connection are the deck
plate, the stiffener and the weld between them.
Usually the deck plate is between 10 or 12 mm thick and the
surfacing thickness is around 10 mm or around 60 mm depending of the
material-.
The stiffeners studied are closed trapézoïdal or "V" shaped.
Stiffener dimensions are about 300 mm wide, 250 mm high and 6 mm thick.
They are typically placed 300 mm apart. Because of the closed section of
stiffeners, welding is carried out on only one side of the stiffener web.
Other types of open stiffeners that were used in earlier bridges are not
considered in this research.
3.1.2. Welding prodecures.
Welding procedures have evolved : originally the procedure was
manual metal arc (tests carried out by Maddox [1*1] and JANSS [15]), now it
is often automatic submerged arc welding. Procedures are still evolving toobtain a smaller lack of penetration (tested in this work).
Several tests have been carried out at IRSID to optimize the welding
procedure. The influence of the edge preparation has been checked and
comparisions made between edges chamfered at 60° or 45° and without
chamfer. The welding energy was adjusted to minimize the lack of
penetration.
From several sets of welding tests it has been shown that without edge
preparation and without chamfer, a satisfactory penetration (lack of penetration £ 1 mm) is obtained for a welding energy of 20 Kj/cm, (figure
3.1), even with a gap of 2 mm between the top of the stiffener web and the
deck plate.
3.2. Stress determination.
3.2.1 . Measurements and calculations.
Stresses in the deck plate to stiffener connection are induced by
the direct effects of the wheel load, the orthotropic steel deck behaves
as a beam on elastic supports (stiffener webs) (Fig. 3.2.).
12 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 21/132
During the two first phases, the stresses near the weld were
measured under traffic loads and with a test vehicle of known axle load.
The stresses were influenced by the temperature and by the distribution of
wheel loads, both in magnitude and transverse position. The temperature
affects the stiffeners of the surfacing and its composite action with the
steel plate. Another factor is that it is not possible to measure a
stress at the crack initiation point.
In order to have a general approach to the behaviour of the welded
connection under a wheel load, it is necessary to develop a stress
calculation method. Stresses have been calculated by a finite band
program. The frame used for the calculation has the geometry of
orthotropic decks found in Belgian bridges (Fig. 3.3.a.). The points where
stresses are calculated are located in the neighbourhood of the weld (Fig.
3-3.b) ; points A' , 3' : in the deck plate ; points C' , D' : in the weld.
Axial and bending stresses are calculated in the cross section in which
they are the highest (section 0 - axis 1 - Fig. 3.3.a).
With the finite band program it is possible to study the influence of the
following parameters :
- longitudinal location of wheel : longitudinal influence lines are drawn
in Fig. 3.11. It appears that at points A' and B' (deck plate) stress values change sign at a certain distance from section 0. Thus the stress
amplitude at point A' and 3' is higher than the maximum stress obtained
when the wheel is on axis 1 ;
- transverse location of wheel : results are presented in the form of
transverse influence lines (Fig. 3.5 and 3-6).
■ surfacing thickness : two surfacing thicknesses are considered :
- deck without surfacing : load is not distributed ;
- deck with a 60 mm surfacing thickness : load distributes through the
thickness at an angle of 1)5° ; no composite effect is considered.
- dimensions of wheel contact area : different sizes of wheel are studied.
13
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 22/132
3.2.2. Stress histograms.
The calculation of the stress histograms used for the variable
amplitude tests were made using the simulation program of Liège [2][7]
[ 8 ] . For each axle of the traffic the program chose at random a transverse
position on the deck plate corresponding to a value of the transverse
influence line. This v alue, multiplied by the load of the axle gave the
stress induced.
The data introduced in the simulation program are :
1. Traffic : the vehicle axles of the Rheden traffic were divided into
four groups according to their wheel type.
2 . Transverse distribtion : the transverse distribution of the vehicles
was obtained from measurements made during the 1st and the
2nd phases.
3. Transverse influence lines : calculated in section 3.2.1.
The histogram obtained is presented in table 3.1 and figu re 3.7..
It was used for the variable amplitude tests.
3.2.3. Equivalent stress range.
To compare the variable amplitude test results with the constant
amplitude ones, the applied stress spectra were analysed according to
Miner's rule in two different ways, each using an S-N curve with a slop of
- 1 / 3 .
a. An equivalent stress range La was calculated in a way that n-cycles of
that stress range have the same fatigue damaging potential as n-cycles
of the stress spectrum, using a third power relationship ;
*° a "(-T7T z
n . Â o . ' ) 1 / 3 MPae E n. i l
b . The equivalent values proposed by the University of Liège [25] in the
report of the 2 d phase [2 5 ], corresponds to the centre of gravity of
the damage distribution (see Fig. 3.7) ;
Z n < Å o <Ao - _ _ L _ _ MPa
3I niAoi
nm
3I niAoiJ
A°m3
in which : Ao^ - individual stress range
rU - individual number of cycles corresponding to AojAora " equivalent stress range
nm - number of cycles belonging to Aom
This definition is not much influenced by a cutting of the high numberor low cycles which produces not much damage.
In this report both method are used.
14
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 23/132
3.3. Fatigue testing and results.
3.3.1. Test specimens.
The tests presented in this section are :
* previous tests : - W .I . (Maddox) [11]
- CRIF (Janss) [15]
* tests of the University of Liège [2]
* tests of I.R.S.I.D [ 3 ] .
The loading mode and the g eometrical characteristics of the
specimens are giv en in figu re 3 .8. and Table 3.2 .
The material used is of the type E 36—^.
General welding procedure characteristics are :
- no edge stiffener preparation- horizontal position
- one run
- no preheating
- no postheating.
- Specific conditions :
W. I . : manual arc w elding
C.R.I.F . : manuel arc w elding
I.R.S .I.D. : automatic w elding (submerged ar c) .U .Lg. : automatic w elding.
The geometrical characteristics of the welds are given in table 3.2.
3 .3 .2. Test resu lts presentation.
D epending on the stress distribu tion in the deck plate and in the
trough, as well as the weld quality (penetration, throat, thickness,
undercut, ...) fatigue cracking may occur either :
a) from the weld toe on the deck plate, point A fig. 3.9., developing in
the deck plate.
b) from the weld root in the stiffener, point D fig. 3.9., developing in
the throat of the weld.
To determine the stress distribution in the specimen, static tests
were carried out. It is noted that in the median axis of the specimen the
loading is biaxial w ith o2/o1 - I /3 (o1 is in the direction of the bending
stresses). This phenomenon has not been taken in account in the S-N curvesbecause designers do not consider biaxial stresses.
15
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 24/132
From these tests the nominal stresses to be used in the fatigue
S-N diagrams were derived (figure 3.9).
- extrapolation of the stress in the deck plate to the weld-toe, Ao.
definition generally used when cracks propagate through the deck plate
from the weld toe,
- extrapolation of the stress in the trough to the weld root Ao , S
definition generally used when cracks propagate through the weld from
the root of the weld.
Four different failure criteria have been used :
N » crack detection by strain gauge ;
N =■ first visible crack ;
N = measurable charge in stiffness of the specimen, or 25 mm. long crack.
N. = end of test.
The results of the tests made at IRSID and at the University of
Liège are given in tables 3.3. Tests with failure in the deck plate and in
the root weld are considered separately.
3.3.3. Failure in the deck plate Aorf.
3.3.3.1. Constant amplitude tests :
These tests determine the fatigue strength of the deck plate at the weld
toe. Results are given in Table 3.3.a and plotted in Fig. 3.10.
Main conclusions are :
- There are no significant differences between specimens with a 2 mm gap
between the top of the sti f f ener web and the deck plate and specimens
with no gap, provided the lack of penetration is less than 2 mm.
The mean Wöhler curve is determined with R = -1 and R 0 - 0,1 in the
weld root for the specimen tested at IRSID.
-1/3 Aod - 26777 N (m = 3 imposed) .
As the standard deviation is 24 N/mm2, the characteristic value for
97,5 ? is Ao = 163 N/mm2 for N - 2 10 6 cycles, de c
- The two experiments conducted at IRSID show a lower fatigue resis-
tance at R = 0,1 than R » -1. However, two similar tests performed
at Liège do not indicate such a detrimental effect.
16
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 25/132
In only two U.Lg. specimens did failure occur in the deck plate
corresponding to R » 0 (only tensile).
3.3.3.2. Variable amplitude tests :
The loading histogram used for these tests is the stress spectrum calcu
lated in section 3.2.2. (table 3.I- and Fig. 3.7). This histogram simulates
traffic effects. Loads were applied at random to the test specimen.
Two tests were carried out. They are plotted in Fig. 3.10 at their
equivalent values (Ao , n ) calculated from the histogram. Them m
equivalent values correspond to the centre of gravity of the damage
distribution, see figure 3.7.
Results are similar to those obtained with constant amplitude loading.
3.3.I. Failure in the weld Ao .s
3.3.1.1. constant amplitude tests.
Tests results are given in Table 3.3.b and plotted in Fig. 3.11.
Main conclusions are :
- the fatigue strength increases significantly when using automatic
welding, this technique allows larger penetration and throat
thickness at the weld.
- The mean S-N curve is determined :
Ao - 17258 N~ 1 / 3 and
the characteristic value for
97,5 $ is Ao - 111 N/mm2 for N - 2.10 cycles,se c
- The tests show the importance of R ratio. To obtained the failure
in the weld it was necessary to have more tension than compression
at the root of the weld :
- 1 < R < 0 in the ULg specimens
R » 0,1 in the IRSID specimen.
3.3.1.2. variable amplitude fatigue tests :
The loading histogram used for these tests is the stress spectra
calculated in Section 3.2.2. modified to obtain failure in the weldRs - -0,5 instead of - 2,0 at the root for the highest stress range.
- 17 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 26/132
The results are plotted in Fig. 3.11. at their equivalent values
corresponding to the centre of gravity of damage distribution.
Results are similar to those obtained under constant amplitude
loading.
3.3.5. Comparison with previous research.
Results from the Welding Institute [1*1], CRIF [15 ], University of
Liège [2 ], and I R SI D [3] are compared in Fig u re 3.11 in terms of nominal
stress range in the trough at the weld root L a (any other representative3
stress could be used) versus the number of cycles to failure of the trough
to deck plate connection M .
The main difference is that in the Liège University, WI and CRIFexperiments cracks initiate at the weld root and the failure occurs in the
weld, while in the IRSID experiments cracks initiate at the weld toe in
the deck plate and the failure occurs in the deck plate.
The results of the tests at IRSID and at the University of Liège
are given in tab. 3-3.
As shown in tables 3.2., the specimens tested by CRIF and by
Maddox, welded by manual arc welding, confirm the importance of lack of
penetration. It is clear from figure 3.11 that the fatigue resistanceincreases significantly when using submerged arc welding, this technique
allowing larger penetration and throat' thick ness of the w eld. Nevertheless
it is shown that cracks initiate at the weld root even with a lack of
penetration of 2 mm. However if the welding operation is properly
optimised, the lack of penetration can be. limited below 1 mm. and, for
alternate or repeated tensile bending in the deck plate, the cracks
initiate at the weld toe, and the fatigue resistance is improved.
f.
V
\
/y
18 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 27/132
3.H. Fatigue life calculation.
The characteristic stress range deduced from the fatigu e tests, defined
for N » 2.10 cycles following Eu rocode 3, are :c
Aa — 114 N /mm
2
, if the crack occurs in the w eld (point D) ;scAa. - 163 N/mm2 if the crack occurs in the plate (point A ) ,
dc
If the traffic composition measured at Rheden is considered, the number of
lorries required to cause failure may be calculated (see 3 .2 ). The results
are given in table 3.4.
Putting there data in perspective, the traffic flows recorded on highways
during the 1st and 2 nd phases generally comprise between 100 0 and 40 0 0
lorries during a working day. Such flows produce, after 100 years, between
20 and 80 .10 lorries.The following comments may be made :
1. The fatigue life calculated in the deck (Ao ) is always a little higher
than in the weld (Aa ) : the hig her fatig u e strength is partially
offeset by higher stress ranges produced by the traffic loads ;
2 . A surfacing of 6 0 mm gives a fatig ue life 3 to 5 times longer than the
unsurfaced deck ;
3. An increase in the deck plate thickness of 1 mm gives a fatigue life
around twice as long.
4. An increase in the thickness of the stiff ener redu ces the fatigu e life
a little.
5. The g iven fatigu e lives are pessimistic, because the transverse
position of the traffic flow considered in the calculation is in the
most damaging position.
6. The given fatigu e lines are too pessimistic for surfaced decks where
the calculation doesn't take in to account a composite effect, that
exist mainly by low temperature.
We may conclude that the required thickness of the deckplate depends
of the expected number of lorries, and the thickness of the surfacing.
- 19
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 28/132
3.5. Crack propagation and lifetime calculations.
The fracture mechanics model has been applied to the stiffener-
plate connection of various structures :
- the IRSID test specimens,- the two temporay bridges of Montlhery and Choisy-le-Roi,
- the bridge of Caronte.
3.5.1. Test specimens.
The calculation of the crack propagation lifetime for the test
specimens presented in § 3.3. was made by the LCPC to calibrate and check
the model. The tested and computed lifetimes are compared in table 3.5.
Various stress levels have been considered from 150 to 3*40 MPa and the
mean stress described by the ratio R presented in § 2.3. was given either
by R = -1 or R = 0.1. The lifetime calculation was made for 2 initial
crack lengths : 0,05 and 0,H mm.
The very good welding conditions (automatic optimised welding),
are likely to lead to small initial defects and the initial crack length
adopted here is between 0,05 and 0,1 mm. In existing bridges, it is
generally assumed that this length may rise to between 0,3 and 0.5 mm. The
agreement between the tests and the model predictions are fairly good,
given the usual uncertainties in such experimentation.
3.5.2. Montlhery bridge.
In this case the stress diagram is fitted in this case by the
polynomial :
o(z) = 7.533 - 2.706 z + 0.481 z 2 - 0.0788 z s + 0.0055 zk
The lifetimes are calculated using the measured stress histograms,
recorded in 1978 during the first phase of this study. Results are given
in the tables 3-6 and 3.7. In order to compare the results with the
classical Miner's approach, the lower limits of the stress intensity
factor AK are chosen as functions of the fatigue limits (at 5 million
cycles) of the S-N curves : AK = f (a , a ) , following the last formula
of §.2.3.
For this bridge the fairly poor welds may lead to the adoption of
well class iJ5 or 50 MPa and the lifetimes calculated from the fracture
mechanics model will be longer than the calculated using Miner's rule.
For good welds (classes between 63 and 71 MPa), both models give the same
-20
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 29/132
both models give the same results for this stress distribution. The sensi
tivity of the fatigue life to the weld class is much higher in the Miner's
model than in the fracture mechanics one ; the latter seems to be more
realistic. In any case, the short lifetimes found here show that this
bridge was not designed for such a heavy and dense traffic.
3.5.3. Bridge of Caronte.
The stress diagram here is fitted by the polynomial :
a(z) - 6.0211 - 3.287 z + 1.075 z 2 - 0.190 z3
* 0.0123 z**
Table 3-7 shows the computed lifetimes for various R and AK . The stress
variations are those measured in the second phase of this research. Due to
the low stress variations, no damage is expected for classes above 71 MPa
and the lifetimes are always very long. With the Miner's rule, thelifetimes become short for the lowest classes...
3.5.1. Bridge of Choisy-le-Roi.
The stress diagram is represented by the same polynomial as for
Montlhery, because the structure is identical and the loading similar. In
this case two traffic flows have been used for computing the stress time
history by the LCPC's program CASTOR. One is the existing traffic on the
bridge, before an increase forecast after the opening of a new motorwaysection, and the other was assessed in Angers (RN 23), representing the
future traffic on the bridge. The influence surface of the transverse
stress in the deck plate along the stiffener-plate connection is given in
figure 3.12.
Tables 3.8 and 3.9 give the fatigue lives computed for both types
of traffic, various AK .The influence of the initial crack length can beS
seen. The choice of AK = 2 and a - 0.3 mm. seems to be realistic. Under
s 0the existing traffic the fatigue life is approximately 200 years, while
under the predicted traffic it falls to 1)2 years (assuming well class 63
MPa). The results obtained by Miner are very close for this class, but
again the calculations are very sensitive to the fatigue limit. Figure
3.13 shows the crack propagation versus time, for various AK and for thes
two traffic flows. It is clearly seen that the crack length (and the
damage) does not grow as a linear function of time or number of cycles, as
predicted by the Miner's law.
21 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 30/132
3.6. Conclusion.
The specimens used in the experiments were welded with automatic
submerged arc welding in an industrial situation. The first step in this
work consisted of optimising the welding parameters. It has been shown thatfull penetration, (lack of penetration less than 1 mm) can nearly be
achieved without edge preparation.
In these conditions, there was no signifiant difference in fatigue
behaviour for specimens with a 2 mm gap between the top of the stiffener
web and the deckplate and those with no gap.
For alternate bending (which best represents the loading in
bridges) with a lack of penetration not greater than 1 mm., the cracks
initiated at the weld toe in the deck plate. Work at the University of
Liège with similar specimnes but with a lack of penetration of 1,5 to 2,5
mm. lead to crack initiation at the root of the weld if the tensile
stresses were higher than the compressive stresses (a m a x > /a /) at this
point. Therefore if the lack of penetration is not greater than 1 mm., it
is possible to exclude cracks in the weld, and to assess the risk of crack
initiation at the weld toe.
The test results allow the required plate thickness to be
determined, depending of the expected lorry traffic flow, and the thickness
of the surfacing (see table 3.1)). It is now possible to choose between the
thickness of the surfacing and the thickness of the deck plate in order to
increase the fatigue life.
22
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 31/132
Stresses
0 .i
Û«/isaa )
70 - SO60 - 7050 - 6040 - 5030 - 4020 - 3010 - 200 - 100
-10 / -0-20 / -10-30 / -20-40 1 -30-50 / -¿0-60 / -50-70 / -60-50 / -70-90 / -SO-100 / -50-110 / -100-120 / -110-130 / -120-140 / -130
TOTAL
;
Number
1319612226351175"27515176
| 12627
6629¿348234316681C685703651S98320
972
40000
Stress-ranges
ha . (N/sra2)
10 - 2020 - 3030 - 4040 •- 5050 - 6060 - 7070 - SOSO - 9090 - 100
100 - 110110 - 120120 - 130130 - 140140 - 150150 - 160
160 - 170170 - ISOISO - 190190 - 200200 - 210210 - 220-
-
Number
6767416324S91650109087260144131425314213481431721117522
19150
TABLE 3.1. : Stress and stress-range hist ograms
at point D' (variable amplitude tests)
- 23
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 32/132
T A B L E 3 . 2 G E O M E T R I C C H A R A C T E R I S T I C S OF T E S T S P E C I M E N S
1
ro
i
GEOMETRIC CHARACTERISTICS(nun)
- deck plate thickness td
- stiffener thickness ts
- stiffener width B
b
- stiffener height h
- location of the load L
- location of the support S,
S2
- type of welding
- gap
- lack of penetration
- fillet weld
W . I .11
6,35
305
150
230
Manuel
5 to 6
4,5 to 5
CRIF
12
6
300
109
250
335
337
Manuel
< 0,5
3,0 to 4,5
3,5 to 4,5
U.LG.
12
6
3Ò0
109
250
85
335
337
Autom.
< 0,5
1,5 to 2,5
4,7 to 6
IRSID
12
6
322
212
226
85
335
335
Autom.
0 or 2
15,5 to 6,5
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 33/132
IO Ol
Lab.
IRSID
H
H
H
H
ii
■i
M
II
"s deck plate
-1
-1 -1 -1 -1 -1 -1 -1 — 1
Ao.d
(HPa)
150 170 200 200 240 240 300 300 340
Aos
(Ml»a)
115
142 107 167 200 200 250 250 283
»1
3000000 947000
135000
245000
N 2
Cycles
470000
N 3
4570000 1432000
.1047000
464000
»A
>5700000
>5670000 5031000 1676000 1069000 1211000
591600 560000 527000
II
II
II
II
II
II
II
II
II
II
U.Lg.
U.Lg.
U.Lg. U.Lg.
0,1 0,1
_ i
-1 -1 -1 -1 -1 -1 ™ x
0 0
amp.var. var.amp.
100 240
200 240 240 300 300 300 340 340
215 199
150 180
167 200 200 250 250 250 283 203
198 105 227 255
750000 22100
850000 208000 403000
248000 345000 135000 120000
522000
950400 66000
4007000 1200000 1900000
712000 434700 410000 405000
1065600 232000
4293000 1562000 2170000
440000 796000 447900 517000 470750
1678000 1315000
753000 791000
TABLE 3.3.a. Failure in the deck. (Ao . at point A ) .
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 34/132
Lab.
IRSID
U.Lg.
0)
U.Lg.
U.Lg.
RS(weld root)
0,1
- 0,63
- 0,71
- 0,96
- 1,0- 0,57
- 0,61
- 0,58
- 0,34
0
0
0
Var.amp.
Var.amp.
Aod(MPa)
240
296
302
333
150139
128
144
282
157
224
206
Aos(MPa)
180
240
245
280
152144
102
142
225
136
182
177
228
252
N, N2Cycles
282.000
2.100.0001.850.000
5.600.000
N,
1.230.400
290.000
276.000
400.000
7.600.000>14.750.000
>18.000.000
1.610.000
510.000
8.900.000
610.000
1.315.000
• 465.000
465.000
TABLE 3.3.b. Failure at the weld root(Åo at point D) ,
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 35/132
T A B L E 3 . 4 .
Fa t igue l i f e
C o n n e c t i o n S t i f f e n e r - D e c k p l a t e
T h i c k n e s s ( m m )
Plate
12
12
13
13
14
14
14
14
S t i f f e n e r
6
6
6
6
6
6
7
7
s u r f a c i n g
0
60
0
60
0
60
0
60
N u m b e r o f l o r r i e s ( 1 0 6 )
à°s ,
2a
71
44
199"
89
494
62
297
4 a d
20
75
45
219
103
647
73
393
27
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 36/132
R
"'M
D
-1
r
-1
-1
-1
0.1
-1
-1
0*(MPa)
150
17Ò
200
240
240
300
340
Initial
dei seta0
(mm)
0.050.100.150.200.40
0.050.100.150.200.40
0.050.100.150.200.40
0.050.100.150.200.40
0.050.100.150.200.40
0.050.100.150.200.40
0.050.100.150.200.40
NUMBER OF CYCLES AT FAILURE
F.M model
Propagation
7286000365000023880001766000908200
5031000255500016720001236000635500
316600Ó16080001052000777900399900
1884000957000626000463000238000
262000133000870006500033000
998000507000332000245000125900
69800035500023200017200088100
IRSID tests
Total
>5700000
>5700000
583100016760004293000
1069000121100015620002170000
232000
591600560000796000
470750
Propagation
20310007290003443000
107600012740001767000
209000
315000548000
350000
Tableau 3. 5 : Comparison of the tested and computed lifetimes
28 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 37/132
CLASS
CECM
3 6
4 04 55 05 66 37 18 09 0
AKs
( M P a v ^ T )
1 1 .1271 . 2 5 71 . 4 3 01 . 6 0 41 . 7 7 71 . 9 9 42 . 2 5 4
2 . 5 5 7
2 . 8 6 1
MONTLHERY
M i n e r
6
81 42 13 35 5
1 0 31 9 94 0 6
M.R.
3 03 13 43 84 45 57 8
1 5 9to
1 AK1 ^
( M P a v n T )
1 . 1 1 71 . 2 4 6
1 . 4 1 71 . 5 8 91 . 7 6 11 . 9 7 62 . 2 3 3
2 . 5 3 4
2 . 8 3 5
CARONTE
M i n e r
3 75 79 9
1 7 23 1 56 0 0
1 3 9 32 8 3 58 0 5 8
M.R.
1.882 1 82 6 9
3 7 1fa >wub>
W
Table 3.6 : Computed lifetimes by two models for various
S-N cu rves and Ak (bridg es of Montlhéry and Caron te)
a0
(mm)
0 . 1
0 . 2
0 . 3
0 . 4
0 . 5
0 . 6
0 . 70 . 8
0 . 9
K O
MONTHLERY
AK
1.430
>>
88
3 4
2 2
17
14
1 211
10
9
, , ( M P a / -
c eu 1 1
1 . 6 0 4
>>
1 1 8
3 8
2 3
1 7
1 4
1 21 1
1 0
9
"S )
2.254
>>
>>
7 8
3 3
21
16
141 2
11
9
CARONTE
AK (MPavnïï)s e u i l
1 . 5 8 9
1>>
>>
3 7 1
1 6 6
1 0 9
8 3
6 9
5 9
5 3
4 8
2 . 2 3 3
>>
>>
>>
4 3 6
1 8 7
1 2 5
9 6
7 9
6 8
6 0
Ta ble 3 .7 : Life tim es computed for various a and AKo s
- 29 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 38/132
I n i t i a lc r a c ka (mm)
0
0 . 1
0 . 20 . 30 . 40 . 5
0 . 60 . 70 . 80 . 91 .
L i f e t i m e s ( y e a r s )
T r a f f i c C hoi s y
3 6 2
1 6 51 0 4
7 66 1
5 14 54 03 6
T r a f f i c A n g e r s
8 2
3 82 41613
11988
3 3 7
Ta ble 3 .8 Lif etim es computed (AK = 0) fo r variou s a (Choisy).t o
CLASS
CECM
3 64 04 55 0
5 6
6 37 18 09 0
AKi
MPav'm
1 . 1 2 71 . 2 5 71 . 4 3 01 . 6 0 4
1 . 7 7 7
1 . 9 9 42 . 2 5 4
2 . 5 5 7
2 . 8 6 1
T r a f f i c
M i n e r
2 63 76 09 2
1 3 8
2 2 44 0 17 6 8
1 4 6 9
CHOISY
M . R .
1 0 71 1 21 2 11 3 2
1 4 7
1 7 62 3 43 6 17 5 4
Traff ic ANGERS
M i n e r
68
132 13 1
5 19 4
1 8 73 6 8
M . R .
2 42 62 83 03 4
4 25 9
1 1 53 3 3
Table 3.9 : Comparison of both models (Miner and F.M., Choisy)
30
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 39/132
Ch anf re in : sans
A n gle f i l : 6 0 'Te nsio n ce (V) : 29In te ns i t é (A) : 550Avance (cm/mn) : 50Energie (kJ/cm) : 19,1
F igu re 3 .1 : Ma crog ra phy o f we ldm en ts f o r op t im izedwe ld ing cond i t i ons
d ec k p l a te wh e e l a c t i o n
' s t i f f e n e r
JBBHB
wh e e l a c t i o n
F igu re 3 .2 : Behav iou r o f c r th o î r o p i e s te e l deck
- 31
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 40/132
- .Y l y
L i
ax e
c
a01x
¥ 'axe 1r-
point where stressesare calculated
^ - x
OX VIEW
r r f
L-kl
thickness :12mmgqqg f \J \ f \J VJ L th'ckness =6mn,
7 955 109 95.5
2100
Figure 3.3a : St ruc tu re used for the calcu la t ion
| (N/mm)
NJSls
Auoet real struct ure
/ / Icalcu la t ion s t r uct ur e
Figure 3.4 : 0 inf luence l ine 0 for a 10kNwheel c irculat ing on axis 2
Figure 3.3b : Detai l
3 2 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 41/132
Figure 3.5 :0 A Influence lines fop a wheel laxlsl ; y=0)
transverse repart i t ion
I
coco
Figure 3.6 :o 0-lnfluenc e lines fop a wheel lax lsl ; y=0) it ransverse repart i t ion
► X
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 42/132
n i
Ini
0 , 3 -A o m
s 9 8 N / m m
-—EL =0,115In i
0 , 2 -
dornage distribution (m = 3)
Figure 3.7 : S tr e s s Range Histog ram s a t P oint D'(var iable ampl i tude test)
34 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 43/132
Figure 3.8 : Test specimen and loading
poste 5
-Stress evolution in the deck plate : point A
-Stress evolution in th e trough : point D
Od 1 ("Pa)
poste 4
Fs lOkN
i i i i i i 0 1 Í » U Ö 15 » d (mm;
C U ("Pa) 400_
_ 9 0 .
_ 7 0
- 1 —
£5
paste 3
F.-IOkN
► 50 d (mm)
Figure 3.9 : Strain gauging of the specimen and nominal stress extrapolation
35
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 44/132
co
Aod
400
320
— 280CU
CL 240
200
i
LUCD
ŒCC
COCOLUaz
16 0
mo
12 0
10 0
80
70
CO 60
50
"1 I I I I N U 1 I l I I 1111 I I I I I 1111 1—I I I I I l i
40 < 1—1 I I I 1111y 2 3 456 8
Ê 0 ULg R=0 Ao CteL ® ULg Ao Var.: + IRSID R=-1: © IRSID R=0.1
105 2 3 4 5 6 8 R
i o5
i o6
i i i im2 3 4 5 6 8 7 2 3 4 5 6 8 n
i o7
I O8
CYCLES NFigure 3.10 : Crack initiation at the w eld toe : A o d
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 45/132
co
A os
4 00
3 2 0
-— 280CU
CL 240
2 0 0 h
LULD2 :CECO
COCOLUo c
160
140
120
100
80
70
cn
40
60 -
50 -
10
CYCLES NFigure 3.11 : Crack in i t ia t io n at the weld r oo t : Ao<
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 46/132
s> S ş
Ve^
Figure 3.12 : Inf luence s u r f a c e o f th e t r a n s v e r s a l e s t r e s s along th e s t i f f e n e r - p l a t e connection
38
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 47/132
crack length [m] t raff ic : Choisy
0 . 0 05
0 . 0 04
0 . 0 03
0 . 0 02
0 . 0 0 1
;
—
- -
"
-
'
— K
— K
- - K
- 0 .
- 1 . 1 2 7
- 1 . 6 0 4 - 2.254
r i ■ ■
l , / '
/ ,' -'
' /
/ ' i / ' /
/ ' / / / !
/ / '
/ 1 ' / /
/
, , . , ' .
" ' ' ' ■ i - - — -
;
;
/
," . ■"
•
;
,
;
■
'
-
0 100
Crack propagat ion depending on the A K S
20 0 , , 3 0 0 time [years]
crack length [m]
0 . 0 0 5 t—
A K S = 1 . 6 0 4
0 . 0 04
0 . 0 03 •
0 . 0 02
0 . 0 0 1
Choisy Angers
J /
' 0 50 100 time [years] 150
Crack propagat ion f o r the two t r a f f i c s
Figure 3.13 : Evolut ion of the crack l eng th with the time lo r the cycles number)
- 39 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 48/132
1». CONNECTION STIFFENER-STIFFENER.
H.1. Types of connections.
In most large orthotropic steel bridge decks field splices are
necessary, because transportation of the complete bridge from the shop to
the site is seldom possible. In general, both longitudinal and transverse
field splice have to be made. In the longitudinal splices only the deck
plate has to be connected. This is mostly done by butt welding and as the
weld is accessible both from above and from below, a good quality weld can
be achieved. The same applies to the transverse butt splice weld in the
deck plate. However, at the transverse splice, the longitudinal ribs have
to be connected as well (figure il.1). With closed ribs, which are usually
used in modern bridges, the most appropriate way of splicing is by welding,but as the welds can only be made from the outside in an unfavourable
overhead position, the quality of those welds will be dubious. Depending on
the location of the splice in the deck, the load on the splice can have a
fluctuating part due to the traffic load, dominating the static loading, so
conditions for fatigue damage are present. Stiffener splices occur
frequently in a bridge deck and fatigue cracks in this connection have
recently been found. An investigation into the fatigue behaviour of
stiffener splices is therefore required.
The Dutch and the Italian partners investigated the fatigue behaviour of
the field splices in this ECSC research. The Italians studied a triangular
shape of the trough ; and trapezoidal shaped troughs were tested by the
Dutch. A triangular shape has been studied by Cunninghame in 1982 [2 2 ].
In 1988 a Japanese IIW document was published which contained fatigue
results on trapezoidal ribs [ 2 3] . Test specimens and fatigue results of the
ECSC research are compared and presented by plotting S-N curves. In these
graphs the Eurocode fatigue design curves are used as a reference.
M.2. Stress determination.
4.2.1. Measurements on a Deck Panel in Pisa.
The specimen tested was a full size portion of an orthotropic
bridge deck (see fig. 4. 2 ). The steel plate, 2000 mm wide, was stiffened
- 40 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 49/132
longitudinally by three torsionally stiff ribs with triangular cross
section, spaced at 600 mm centres, and by two flat stiff eners (200 x 12
mm), to reproduce the transverse continuity of the deck.
The stiffeners were made of 6 mm. plate which had been cold formed. These
passed through the cross beams to which they were welded with fillet welds.The cross beams were a double »T' section laid at a centre distance of 3500
mm. The 12 mm thick web of the crossbeams had 25 mm radius circular
cut-outs at the apex of the troughs.
A 100 kN proof load was applied, using a hydraulic jack, through a
200 x 300 x 50 mm thick reinforced neoprene plate : the load was controlled
by a force ring gauge.
Forty five loading positions were tested on the deck ; strains were
measured at each location.
Strains were measured using electrical strain gauges located on
the deck plate, at the apex and on the webs of the stiffeners.
The deflections were measured at 88 points located under the stiffeners and
the cross-beam.
Diagrams and tables of the deflection and stress measurements are
presented in [J|].
1.2.2. Calculation of the stresses.
In order to study the static behaviour of the deck undergoing
examination, an extension of the classic HUber's method was adopted [18]
where the variable section of the crossbeams is taken into consideration,
as well as their shear strain. Using the simplifications introduced by
Pelikan and Esslinger [19], one obtains [20] the definition of a simple
analytical model to calculate the influence surfaces of the continuous
orthotropic deck on flexible cross beams. The differential equation that
governs the problem was resolved using the Levy's method [21]. The sections
of the theoretical deflection influence surfaces of the central ribs an the
stress influence surfaces at the apex of the central rib are presented in
- 41
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 50/132
The sample tested was also analysed using F.E.M. The code used was
MARC implemented on an IBM 3090 computer, whilst the finite element adopted
was a thin shell element with eight nodes with zero degrees of freedom
(element n°72 of the MARC library). The load (100 kN) was applied on a 20 x
30 cm. rectangular surface with its centre coinciding with that of thedeck. A comparison between the results obtained in this way and the
analytical and experimental ones, reveals a close correspondence. Thus, for
theoretical investigations, the analytical method was chosen, because of
its accuracy and its simplicity.
Some theoretical and experimental influence lines are compared in
figure 4.3. (deflections) and in figure 4.4. (stresses at the apex of the
central rib). In the diagrams, .the theoretical curves are shown as acontinuous line, while the experimental results are shown as a dotted line.
A study of the results reveals a close agreement between analytical and
measured values.
4.2.3. Stress spectra.
The stress spectra was obtained by means of the University of
Liège simulation program. The level crossing and the Rain-flow histograms
were calculated for the Rheden traffic on the influence line of the detailtested at T.U. Delft (Fig. 4.5. : bending moment at mid-span of a
continuous beam).
4.3. Test results of the University of Pisa.
4.3.1. Fatigue tests on type ' B' specimens.
4.3.1.1. Test specimens.
The Fe 51 OC specimens, 2000 mm long, are made of a triangular rib
obtained by the cold forming of a 6 mm thick steel plate welded to a top
plate 600 mm wide and 12 mm thick (figure 4.6).
Along the centre line of each specimen, a type I or a type II joint was
shop fabricated using the same procedures as those used on site.
In Figure 4.6 shows details at the tested joints the procedure. In type I
joints, the ribs stop about 100 mm short of the end of the deck plate.
42
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 51/132
In type I joints, the ribs stop about 100 mm short of the end of the deck
plate. The two ends of the top plate - one of which has the backing strip
welded to it (S1 w elding ) - are positioned w ith a gap of about 6 mm, and
then automatically welded.
The missing rib element is then inserted and manually welded in the
overhead position (backing strip weld S 3 ).
In type II joints, the top plate is about 100 mm short of the end of the
stiffener.
The stiffener webs are butt welded, with complete penetration manually
with coated electrodes. First, the internal part of the ribs is welded in
ascending vertical position. The root of the internal weld is ground
before the external weld is placed in the overhead position. The joint is
completed with the insertion of the missing top plate portion, theexecution of the S1 flat position welding and the manual overhead
remaining welding S2 between the top plate and the ribs.
All the w elds were checked by means of visu al and magnetic controls. The
butt weld, were also 100 % X-rayed and repaired where found (once only)
to be unacceptable according to the UNI 7278 Italian norms.
The fatigue tests at constant stress amplitude, were carried out on nine
type I joint specimens and on eight type II joint specimens.
The specimens were simply supported (at 2400 mm span) and the fatigue load
applied at two points 200 mm apart of the centre line using a pulsating
hydraulic jack w ith a frequency of 1 H z.
The load was applied though 50 x 60 mm. rectangular pats of neoprene, 10
mm. thick, between the mobile jack head and the top plate.
The strains at the apex of the ribs were measured using electrical strain
gauges, so placed as to determine the nominal stress amplitude without
taking into consideration the presence of local peaks of tension.
During the tests the minimum nominal stress was kept at a constant 1.5
kN/cm2 for all of the specimens.
Each test was stopped when failu re was reached, as recognized by the
specimen's loss of stiffness (an increase of one centimetre in the maximura
deflection under load), or when eight million cycles had been completed
without breaking.
4 .3.1.2. E xperimental R esults.
In table 1.1. the type of joint, the nominal stress range at the
lower part of the weld and the number of cycles to failure are shown foreach test.
43
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 52/132
In specimen 1 the first crack appeared in the fillet weld of the backing
strip, while a second crack appeared and propagates in the weld ; in
specimen 2, cracks initiated in both welds but only one crack propagated.
In specimens 3, 6, 7, 10, 11, 12, 13, 15, 16 and 17 cracks started in the
weld, at the apex of the rib, and propagated in the weld.
In specimens 4, 8, 14 cracks started at the apex of the rib in the parent
metal and propagated in the plate.
In specimen 5 the crack started in the weld at the apex of the rib and
propagates both in the weld and in the plate.
Specimen 9. no cracks occured in the rib, but three longitudinal cracks
appeared in the top plate : two at the position of the rib to top plate
connections and the third in the middle of the plate.
In figure 4.7 the results obtained and the mean life curves concerningtype I and type II joints are reported.
4.3.2. Fatigue tests on type 'A' specimens - (full size panel).
4.3.2.1. Test specimens.
In order to check the application of the fatigue results obtained
on type B specimens to the real deck joints, fatigue tests were carried
out on two large specimens with type I joints which were obtained by
cutting the specimen used in the static'test across at the centreline (seefig. 4.2).
The panel was supported on two crossbeam with an overhanging canteliver
section which was loaded by two concrete blocks of 54 kN total weight.
The pulsating fatigue 'load, applied through a 20 x 30 cm. rectangular
plate placed in the middle of the span, caused a nominal stress range at
the lower apex of the central rib weld equal to 22.5 kN/cm2 and a minimum
stress of 1.5 kN/cm2, reference being to the stress induced by the ballast
and the deal weight of the panel.
4.3.2.2. Experimental results.
The first specimen failed after 240000 cycles, the second one
after 260000 cycles. In both cases the crack initiated in the weld at the
apex of the rib and propagated in the weld toe.
In figure 4.7, the results obtained on type B specimens with type I joints
and those obtained on type A specimens are compared.
The comparison reveals close agreement, within normal experimental limits,
between the results obtained on the two types (A and B) of specimens.
The slightly lower fatigue life noticed on type A specimens is probably
due to the higher level of residual stresses present in these specimens.
- 44 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 53/132
4.4. Test results of the T.U. DELFT.
4.4.1. Tests specimen.
The specimens for the bending tests were single rib specimens as
depicted in figure 4.8. Two types of field splices were selected ;Type A : Butt splice with backing strips with varying root gap (0, 2 and
4 mm).
Type D : Butt splice with a V-groove and backing strips (root gap 4 m m ) .
The ribs were a rolled trapézoïdal section (steel grade Fe 510)
the dimensions of which conformed to F.K.H. - Trapezprofile nr.
2/325/6. As the usual spacing of the ribs is 600 mm, the width
of the deckplate in the specimens was also 600 mm, in order to
get the same position of the neutral axis as in an actual bridge
deck. During the fabrication of the test specimens, the welding
conditions on a real bridge deck were imitated because test
specimens made with special care under favourable conditions
would not be representive.
The ribs were welded on a 8400 mm. wide plate, at the proper
spacing of 600 mm., in a downhand position. Each rib was in two parts with
a gap in between to make the splice. Then this assembly was turned over
and the field splices were welded hampered by the adjacent ribs as it
would be on site. The welds in the bottom of the ribs were made in the
overhead position and the welds in the webs of the ribs were made by
upward welding. After completion of the splices, the assembly was cut into
fourteen test specimens and the end plates were fixed with fillet welds.
The test specimens were made by a fabricator with experience in making
orthotropic steel bridge decks.
4.4.2. Testing and measuring equipment.
As mentioned, a four point bending test was chosen to study
fatigue in the rib splices. Due to the fact that tests in the region of
ten million cycles were planned, two test rigs were buil t. Part of the
experiments, mostly the variable amplitude tests, were carried out using
servo hydraulic test equipment operating in closed loop control with load
feedback. The main part of the constant amplitude tests was executed with
loading equipment from Losenhauser. To avoid any secondary effects, all
supports in the test rigs were provided with hinges or roller bearings.
- 45
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 54/132
Each test specimen was instrumented with a number of strain gauges,
varying from 9 - 52 locations, before testing. Strain measurements were
carried out dynamically to check the applied stress range. Furthermore,
strains were monitored 2H hours a day to obtain information about and
location of crack initiation.
Measurements of crack growth were carried out during a number of
tests. This was done by periodic visual inspection with a magnifying
glass. It was only possible to measure crack length at the surface of the
specimens.
As far as possible four stages in fatigue failure are expressed in
number of cycles :
NI : Moment of crack initiation given by 10 % reduction in strain measured
by the gauge nearest to the crack.
N2 : Moment of visuable crack becomes visible.
N3 : A surface crack length of 50 mm.
N4 : End of test with extensive through cross section cracking (leading to
loss of specimen stiffness causing limitation of the actuator stroke)
and/or loss of symmetry (causing unacceptable side load on the
actuator bearing).
i|.i*.3- Constant amplitude tests.
i».11.3.1. Tests results.
The fatigue results of the constant amplitude tests are presented
in figure H.9. and table H.2. by plotting the a S-N relationship, on a
log-log scale. The normal stress in the bottom of the rib in the middle of
the splice, due to pure bending, was chosen as the main stress parameter
in this figure.
In all the specimens, the crack began in a weld between the rib
and the splice plate. In most cases, the starting point was located just
above the bend at the bottom of the rib. At this location the stresses are
about 20 % lower than in the middle of the bottom weld, where cracks
might be expected to start because of the higher bending stresses. In one
case the crack started in the side of the web at a location where the
stresses are about 70 % lower than in the middle of the bottom weld.
With some specimens it was possible to continue the testing forsome time to study the behaviour of the crack. The cracks propagated more
in the side weld than in the bottom weld, eventually the crack in the side
weld propagated into the base metal of the rib.- 46 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 55/132
To study the unexpected crack initiation points, some of the
cracked specimens were cut open. Inspection of the inside revealed local
defects, such as bad penetration and slag inclusion. The crack location
can be further explained by the welding procedure. The welds started are
finished just above the bend near the bottom of the rib and a tack weld
was also placed at this location.
Depending on the weld geometry and root gap of the weld, the first
visible crack N2 was noticed at 51 - 98 % of the number of cycles to
failure of the welded connection (N-U). The moment the invisible crack was
detected by measuring strains (N1) varied between 5 and 75 % of the number
of cycles failure (NU). For two specimens no cracks were detected by gauge
but one of the welds of these tests specimens failed very suddenly over 50
- 75 % of the total length of the weld. This phenomenon can be explained
by the poor quality of these particular welds.
1.1.3.2. Effect of the root gap.
Comparing the results of the fatigue tests from figure 1.9. it
appears that a weld with a zero root gap results in a fatigue life far
below the weld with a root gap of 1 mm. (a factor 18). A welded detail
with a root gap of 2 mm. gave variables results. At a level of 163 MPa it
gave a fatigue life comparable with the fatigue life of a detail with a 1mm. root gap but at a lower stress range level, about 110 MPa, the fatigue
life was a factor of 12 lower (Fig. 1.10).
1.1.3.3. Effect of the weld geometry.
Changing the weld geometry by using a V-groove did not give the
expected improvment. However, it is clear that it is easier for the welder
to make a better weld using a V-groove as a butt weld. The disadvantages
are that both sides of the detail have to be prepare and it is necessary
to use more welding material.
1.1.3.1. Fatigue limit.
From the results it appears that for the specimens with a root gap
of 1 mm. as well as those with a V-groove, no fatigue cracks were disco
vered at a level of about 90 MPa after testing for ten million cycles. It
can therefore be concluded that for this type of detailing we are almost
47 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 56/132
in the neigbourhood of the constant amplitude fatigue limit. For specimens
with zero root gaps however, several cracks were discovered in the bottom
side of the rib at a very early stage at a stress range level of 83 MPa.
Due to the bad results for this detail it is expected that there will be
no fatigue limit.
4.4.3.5. Comparison with previous Dutch tests.
In figure 4.10. the test results of the specimens with a root gap
of 4 mm. are compared with previous Dutch tests [24]. It appears that the
fatigue failures of the specimens tested at the high stress range levels
fall between the scatter band of the previous tests. It can therefore be
concluded that these fatigue results can be used for a weld classification
for this detail.
4.-4.3.6. Weld classification : S-N curves.
Ignoring the fact that cracks did not initiate at the bottom side
of the rib, it can be concluded that for the rib splice with a root gap of
4 mm., a weld class 80 (according to the Eurocode 3) can be recommended.
If the crack initiation point is taken into account the classification
reduces to a weld class 63. This values are to compare with the values
given in last draft of the Eurocode.
4.4.3.7. Calculated fatigue life.
Using the simulated stress spectrum for the field welded splices
(fig.4.5) and assuming that the detail can be classified as class 80
according to Eurocode 3, a fatigue life of about 75 years can be
calculated. Further optimisation of the detail seems to be unnecessary.
However in a lot of existing bridges welds were made with small root gaps.
Here the fatigue lives will be very short ; first failures have already
been discovered. To assist with the maintenance of these bridges it is
necessary to know how to repair those welds in an economic way and how to
calculate the remaining fatigue life after repair.
4.4.4. Variable amplitude tests.
4.4.4.1. Load spectra.
In the working group meetings it was decided to use load spectra
from the earlier ECSC Phase 1 and 2 research for the variable amplitude
tests of the third Phase. In the computer assessment programme of theUniversity of Liege, it was decided to use the traffic flow of the Rheden
48 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 57/132
Bridge. Results of the simulation for the field splice in a rib are
given in section 4.2.3. Analysis of the spectrum (figure 4.5) showed that
the stress range < 18 MPa caused only 7 ? of the total damage of the
sepctrum.
However, these stress range classes amount, to 84 % of the total number of
cycles. So leaving out these classes saves a lot of testing time. The
remaining stress ranges (18 MPa - 82 MPa) had to be raised a level above
the assummed constant amplitude fatigue limit. For testing techniques it
was necessary to leave out the highest stress range classes, which
accounted for only 5 J of the total damage. As well as , the simulated load
spectra, for one of the specimens a measured spectrum was used. A review
of all sepctra used is given in table 4.3.
To compare the variable amplitude tests results with the constant
amplitude ones, the applied stress spectra were analysed'according to
Miner's rule in the two different ways explained in section 3.2.3«
4.4.4.2. Tests results.
The fatigue results of the variable amplitude tests are presented
in figure 4.11. by plotting the S-N relationship, on a log-log scale.
The location where the cracks initiated and the crack development
were the same as those found in the constant amplitude te sts . The first
visible crack N2 was noticed in all cases at about 80 % of the number of
cycles to failure of the welded connection (N 4) . The moment the
(invisible) crack was detected by measuring strains (N 1) , varied between
69 and 76 % of N4.
4.4.4.3. Comparison with C.A. - tests.
- Test specimens with a root gap of 4 mm.•under simulated spectra.
There is a good agreement between the constant amplitude tests and the
variable amplitude tests using the Miner's calculation. Furthermore no
cracks were found in a specimen A.1.8. loaded to twice the simulated
spectrum after 48 million cycles. The maximum stress range of the
spectrum of this specimen was 132 MPa.
- Test specimen with a root gap of 4 mm under measured spectra.
Specimen A.1.6. was tested with the measured spectrum of the Forth
Bridge. Comparing the fatigue strength with the constant amplitude test
results, the spectrum showed to some degree a better fatigue life.
- 49
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 58/132
* Test specimen with V-groove under simulated spectra.
The fatigue endurance of this specimen D1.1.-V w as about 8 times that
calculated from the constant amplitude test on this type of weld
geometry using Miner. Comparing the fatigue behaviour of the relevant
speoimens, the fatigue behaviour of the V-groove specimen is almost H
times that of the specimen without the v-groove. More tests on this
detail are necessary to confirm this difference.
Comparing the results it appears that applying the measured spec
trum (A.1,6) resulted a very small difference. Using the measured
Spectrum (specimen A.1.6) instead of the simulated spectrum gives not a
significant difference in fatigue life.
i\.i\.5. Conclusions.
Cracks in these welds always started on the inside where
inspection is impossible. When a visible crack is located the total weld
will fail very soon. Repairing the weld must therefore be done as soon as
possible.
- Constant amplitude test ;
The results of the tests showed that the root gap of these kind of
welded connections must have a minimum width of 4 mm. to achieve a
welded detail class 8 0 according to Eurocode 3. If a weld can be made
without penetration defects and slag inclusions the classification may
be higher. F or the test specimens with a root g ap of 4 mm., no cracks
were found at a stress range of 9 0 M P a , (compared with the 6 0 M P a
constant amplitude fatigue limit of class 8 0 ). S o a knee-point at tw o
million cycles instead of five million cycles is possible. Changing the
weld geometry did not give the expected improvement, however the number
of tests (two) is too small to draw a definite conclusion.
" Variable amplitude tests t
F or the traditionally welded connection with a root g ap of H mm., there
is good aggreement between the constant amplitude and variable amplitude
tests, using Miner's calculation. I n this part of the programme the
V-groove (one test) resulted in a much better result than the welded
connection tested under a constant amplitude load. More tests are
necessary to confirm this difference. The difference in fatigue life
using a simulated spectrum seemed to be small.
50 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 59/132
H.5. Comparison with other research programs.
In addition to the ECSC research described in this chapter, the
fatigue behaviour of field splices in ribs of orthotropic steel decks
has been studied by Cunninghame [22] and Yamada [2 3]. A triangular shape
was studied by Cunninghame in 1982 and in 1988 a Japanese IIW document,
published by Yamada, contained fatigue results for trapezoidal ribs. The
results of the tests are given in figures 4.12 to 4.14..
From the UK-research it can be seen that, with the exception of
one test, all results are situated above the class 125 of the Eurocode
S-N curve. As with the Dutch results, the location of the fatigue cracks
was unexpected. All the failures initiated at the root of the weld on
the flat web of the stiff ener rather than at the more highly stressed
apex. Examination of several fracture surfaces showed no single
initiation point. It is concluded that the crack initiation point is
determined by residual stresses due to the welding procedure. Gathering
the "Pisa-tests" (type I) and the "UK-tests" together it can be
concluded that for triangular shaped ribs containing a weld with backing
strip a Eurocode class 112 can be considered (figure 4.12).
Confirming the Dutch research, the great influence of the size of root
gap on the fatigue strength was found in the Japanese research.
Furthermore the fatigue strength was affected by the residual stresses
in the direction of the rib which depends largely on the welding
sequence. Comparing the results with the Eurocode S-N curves, it can be
concluded that field splices with a root gap of 3 mm. or more are above
the class 71 curve. Gathering the "Delft-tests" and the "Japan-tests"
together it can be concluded that for trapezoidal shaped ribs containing
a weld with a backing strip and a root gap greater than 3 mm., a
Eurocode class 71 can be considered (figure 4.13). However with small
root gaps the classification can drop to 36 or less (figure 4.14).
4.6. Conclusions.
A lot of data are available concerning the field welded rib
joints. A first comparison showed ;
- The butt weld connection gives lower fatigue behaviour as the connec
tion with braking strips (fig. 4.7) ; but the fatigue behaviour of
this last connection seems influenced by local defects, that are
depending of difficulties of realization in a bridge working site.
- 51
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 60/132
The better behaviour of the triangular ribs compared with the
trapezoidal ones, for a connection with bracking strip and a root gap
greather than 3 mm. :
¿ 0 »11 2 N/mm
2
for triangluar ribs ;cÄ a = 71 N/m m 2 for trapezoidal ribs (that corresponds to
cEurocode 3 prescription).
- The reduction of the fatigue strength when the root gap is smaller than
3 mm. ; La < 36 N/ mm 2.
- The influence of residual stresses and defects due to the welding
procedure.
- Using Miner's calculation there seemed to be a good aggreement between
the results of the constant and variable amplitude tests.
More detailed analyses of the available experimented data are
needed to give a general conclusion for design and practical recommenda
tions.
From the above, it follows that for the orthotropic deck details
whose dimensional characteristics are described, it would be desirable to
define in the codes, S-N curves which take into account the type of joint,
the presence of defects and here control and, above all, the construction
procedures and thus the level of residual stress (for example : the
starting point of welding). The S-N curves should be lower for those
details which do not satisfy minimum quality requirements. Naturally,
because of the complexity of the problem, the conclusions proposed here do
not pretend to be in any way definitive, but rather a reference point for
future investigation.
52 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 61/132
Speci-.en
Jí.
1
->
3
4
J o i nz
Type
I
I
II
II
5 ! I] C
5
7
S
3
10
11
» 113
14
15
16
17
I T
I
o-rsnçeI KW/en = ]
19.50
22.50
22.50
19.50
17.50
17.50
22 . 50
II 1 14.00
I
T T
I
Ţ
II
1 1
I
II
I
17.50
19.50
19.50
Cycles ac failure
13S0000
53S0OO i
251000
939700
321000
459500
463000
6040000
8100000
335000
1200000 "
22.50 1 S560CO
22.50
17.50
19.50
305000
1930000
1657000
12.50 1 7073000
19.50 1 1622000
Test results o f Pisa
TABLE 4 . 1 .
- 53
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 62/132
SPECIMEN
A.1.1.
A.1.1.
A.1.2.
A.1.2.
A.1.3.
A.1.3.
A.1.4.
A.1.4.
A.2.1.
A.2.1.
A.2.2.
A.2.2.
A.3.1.
A.3.1.
A.3.1.
A.3.2.
A.3.2.
A.3.2.
A.3.2.
D.l.l.
D.l.l.
D.I.2.
D.I.2.
VELD
1.
2.
1.
2.
1.
2.
1.
2-
J
2.
1.
i »
1.
1.
1.
2.
1.
nl
0.157
2- *
V•
-
9.085
•
-
-
0.180
0.239
.
-
-
0.713
0.035
0.035
-
0.175
0.180
0.203
0.223
-
0.728
-
n3-
•
9.085
-
•
-
0.180
0.244
.
-
-
-
0.039
0.029
•
0.180 .
-
0.253
0.240
-
-
-
n4> 0.833
0.833
9.298
> 9.298
>29.582
>29.582
0.245
> 0.245
> 0.668
0.668
> 0.779
0.779
0.445
0.445
> 0.465
0.327
0.327
0.327
> 0.327
>10.990 .
>10.990
0.798
> 0.798
At>r[KPa]
150
Ï50
105
105
90
90
233
233
163
163
110
110
153
153
153
S3
83
83
83
lêo
CA?[ 3]
'M'Vi' l ìî4 :u
4 ƒ
4 J
2
2
2
2
0
0
0
0
0
0
0
H '
1 J
to - nominal stress ranga bottoaside trough.
n - number of cycles x 10 .
n. - initiation by strain gauge.
n, - first visual crack.
n, - length of crack equal to 50 va.
n, - failure of the veld.4
Table 4.2. Results constant amplitude tests
5 4 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 63/132
STVÜLATE3 S7ECTP.A; TABLE 4 . 3 .VtRTABLE AMPLITUDE TESTS ! T- U. £1 ITT
N U M S E S
O ?
CYCLES
E1 3 0
s a i a
5 5 7 0
5 41 0
51 2 0
« 6 2 0
3 5 0 03 7 0 0
3 3 3 0
2 P O O
2 5 3 0
1970
1 6 7 0
1 5 5 0
5 0 0
1 0 5 0
5 0 0
6 A0
4 4 0
3 3 0
4 8 0
3 10
11 0
12 0
^i(iooo) lM?ft)
TEST SPECIMEN
y-AS'L-10 SPEC??.*,: inF o r t h
A.1.5.
D.I.l.v.
80
'EB
56
10 4
112
12 0
12 813 6
14 4
15 2
16 0
16 8
176
1E 4
19 2
2 0 0
20 8
216
2 2 4
2 3 2
2 4 0
2 4 8
2 5 6
2 6 4
A.1.7,
£0
66
72
78
E4
5 0
5610 2
10 8
114
12 0
12 6
13 2
13 8
14 4
15 0
15 6
16 2
16 8
17 4
18 0
186
19 2 .
19 8
A.1.8.
4 0
4 4
4 8
5 2
5 5
6 0
6 4£3
7 2
76
S O
£4
8 8
5 2
9 6
10 0
10 4
10 8
11 2
116
12 0
12 4
12 8
13 2
K V M 3 E R
0 ?
CYCLES
4 0 E 6
3 4 5 6
3 3 6 6
2 5 0 2
2 0 3 4
1618
18181215
1341
1044
£2 3
9 0 9
8 10
7 7 4
8 5 5
7 9 2
6 6 6
6 21
4 5 5
. 5 5 8
4 14
3 4 2
17 1
1E 0
i jri ( 1 0 0 0 ) i " ? B j
T E S T S P E C I M E N
A.1.6.
£0
£8
5 6
10 4
11 2
12 0
12 813 5
14 4
15 2
16 0
16 8
17 5
1E 4
19 2
2 0 0
2 0 8
2 16
2 2 4
2 3 2
2 6 0
2 4 3
2 5 6
2 6 4
I nt- 61 3 S O
to [M?a] -
¿S [M?al -a 1 '
n - 4 5 6 10a
13 5
153
10 1
115
68
7 7
31095
15840
14 5
1S 2
V l 0 3 )Dll.V
4 7 6 0
A.15
10001200 4 7 5 0
1.4201.200
n 2 ( 1 0 3 )
5 1 5 012301350 5 4 0 0 1.470
1.620
1.770
n ( 1 0 3 ) 1270
5 1 9 0 6 2 5 0
6 5 0 04 ( 1 0 3 ) 6 2 7 0 1460 4 8.100
5 5 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 64/132
P A V E M E N T
D E C K P L A T E
L O N G IT U D I N A L R I B
L A T E R A L R I B
R E L D W E L D E D J O I N TM A I N G R I D E R
o r S T R I N G E R
D E C K P L A T E
B A C K I N G S T R I P
F IE L D B U T T
W E L D J O I N T
L O N G I T U D I N A L' R O U G H R I B
C O N N E C T I N GR I B
F'5Ure 4-1 : Tthotropfc , t „ i b r i d g e deck
56
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 65/132
?
?
i A
-y -
'T" I
I'
3S00
B
: : ;
B
3SO0/2
*yf
■ i -
i -! A
' T "
U J
section A -A
m
i i I ' ! i l
section B-B
Figure 4.2 : Type A specimen (PISA)
57
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 66/132
WUmm) x=525cm y=90cm 4.3a
X(cm]
0
1
2 3
W ' (mm)
r — 1 1
x=52 5cm
. '
y=60ciT
1050
X
4.3b
0
1 2
3
W (mm)
! i I 1
Y = Ç f t
^ " ^ - ^ J
ì ì r m
—•<
v=pn
>s
rm
1 • i
1
1050 - — w » .
X
4.3c
X(cm)
0
1
2
3
i\ / _ i
■ \ ■■ 1
x=58
<
3,3cm
■
y=60 cm
1050 ^ -X
4.3d
F igure 4.3 : Compara ison b e t w e e n t h e o r e t i c a l and e x p e r imen t a l
r e s u l t s ( d e f l e c t i o n s )
- 58
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 67/132
0
s
10
\'""
1050— * -
X
O'lkN/cm2) x=525cm y=90cm
¿.¿a
0
5
10
0 (kN/c
r i
m j
i 1
>
^ s
:=525c
S
m y=(30cm
1050^ -X(
UMb
_0
5
10
OÎ(kN/cm2) x = 700cm y=90c m
LAC
:K:1050^
X{cmJ
Figure 4.4 : Comparaison between t he or et ic al and e xperim entalresu l t s (s t resses)
59
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 68/132
n¡ [%] i
70
60
50
CO
30
20 -
10 '
2
D 3 [% ]
5 - .
5 - .
4 - -
3- -
2. .
1- .
o-2
f . 63.5
• ■
■
-,
l_ S ' niula
n
7.0
r-
A s IB
h
i
. 1 . 16.2
1 Nummer of Cycles 1% )
Rain flow histogram Rheden traff ic
e d used in tests , /
1 i
5
D3 -DANA CEI'/.} 88.0
Ì JV L r
6t ^
0.2
5 N//7V7J
56 82 H 1
5.0
S], ln_
; 62
N U 2
In.- 6138 ¿a - - 33.8 N/nm
I i : -j ASm » 38.3 N/nm , a - 4450
m
En.- 37.740 ¿O- - 18.7 N/ma2
i e 2 H
¿ S B - 40.5 N/mm , D - 4091
Figure 4.5 : Detai l t e s t e d in Dal f t - 60 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 69/132
l \S -j*l4
j . í j
-^o»- l!
Js^M22_Äi)
A L
! monjol "Ţwe/ch'n ţ
h fc--^ ■*■■<--■
Type 1 SECTION •• / -A
I 100 I fl» !
^-•r
Type 2 SECTION •■ A-A
MS '
V&tjp&.-X /£%>S ■r-M™
Figure 4.6
- 61 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 70/132
co = 1
— — - T
-^
_ ~
,_ —. _
^^
—
— —* —̂
^mm
—
— ™ *
""
1
■ 1 1
7 /
/5> 4
i i
i i i
i
i
i i ■
■ i i i
i i ,
j /
u / A /
/ •
•
i \ \
J l l i i l l U i l . l l i l J i i i 1 1 J 1 i 1 i 1 t I 1 1 1 1 1 : 1 1 | [_ ^~^
a i a < ^ M 1 1 M M H
Q) O Q) ~ O i O i O i >i >, >,
H E" H
• « + r
• ' —
—
—
—
—
fc_
— — — m
~
m
I m i i n i t l i i i n i i i i l i M i l i i i i 1 i i i i 1 i i r r 1
■ O ^
■ CD
■ LO
■ 3 *
■ ro
ru
r^ CD
o * - " 1
to LO
Z?
ro
OJ
CO
O ro*—'
CO
LO
ZT
ro
OJ
LO
O C0'
F~^
CO
LO
3 *
ro
OJ
~o
zz.
CO LU I
CJ > -
o w OJ > C 3 1_>
Z
to
ai Q . > ■ .
•*-•o n i
— 01 Q .
4 -
C OJ QJ
- 1 -
<U - O
C O
J2
ra Q . E o
C»;
QJ C 3
I I
O
o r j *
O O J CO
D O O J
o 3 "
O J
o o OJ
o LO • — 4
O O J
O O
O CD
a r—
o CO
o LO
o =r
(edW) JS 30Nby SS3ÜÍS
62 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 71/132
1500
3525 1000
V v
r^ \ -4 1-
1500
3300
TYPE A. A - 1 root gap = 4. A - 2 ,. = 2 . A - 3 .. = 0 .
TYPE D.
r6 i W
E^sl ^ = 3
■ƒ 0x4
\ \ \ \ \ \ \N
<s°
l„root gap
i — 6
Sl x ^ K a=3
-ƒ30x A
N \ W N \ N
300 550
325 WELD AREABACKING STRIP
Figure 4.8 : Se lected t yp es of f ie ld splices in the ECSC rese arc h
- 63
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 72/132
CO K : o
o o
ce m
U J
U J
t— CO
o
a . o en t— O zs z t—
Cd
o
o 00
co
cc
UJ
o
I
I ! . J
fr ¡5
X —
<
c o c
U I a o o o ce
co O
o ,
í»»
I O
m
^
A . 1 1 1 1
■ <
ce o •
o o
1 —
co 1 —
t / ]
^ ' » - co
X
O I J J -
t—o : cc»— o o
co -
" m i n i m i n i i i i i i i i i i i i i i i i i i
UJ c
?*" I a> o
»—COCO
I
r» ( O
I O
■ »
o
CM
I O
O en ,
r» I O
I O
-*•
I O
—i
— — s 3
CO
) C 5
> -
O L i _
O
ce U J 0Q
3 to ni c_
4 -
ni 1 -
•• a \
«* 0J
c_ 3 TI a .
o O - « ■
O ( O
o
o CM rO
O co CM
o o o co CM —
o o t o -■»■
o CM
o o o o o> oo
< [ D d W ] (3QIS H0I108 TVNinON) 3 o N V cJ S S 3 el 1 S
64
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 73/132
O)UI
F I E L D - W E L D E D R I B J O I N T S OF O R T H O T R O P I C S T E E L 3 R I D G E D E C K S
( S - N C u r v e s a c c o r d i n g to EUROCODE 3)
AII
o
om
O
-<OC
CO
coLU
CU
t —
CO
400
360
320
280
240
200
180
160
140
120
10 0
90
80
70
60
50
"I 1 I I I I I I I "I—I I I I I II T I I I I I I I I 1 1 I M M b
C O N S T A N T A M P L I T U D E T E S T S E
F.H.K.-TRAPEZPROFIEL 2/325/6 Fe 510 j=
TYPE A : Butt spile« with back-up strips Z
A ROOT CAP 4 mm (ECSC HOLSTEIN 198 9)1
4 mm (TUD TROUP 1974) -
— run-ouI —
40
1 0
.TU-DELFTS t e v i n L A B 0 R A T 0S t e e l S T R U C T U R E
I i i i i i 1 13 4 5 6 7 9
I H -r-l-M-H4 5 6 7 9
1 0 " 10" 10' 10
N U M B E R OF C Y C L E S (UNTIL TOTAL FAILURE) [N ] >
Figure 4.10 : Comparison with previous research T.U.D. STST-005.GRA
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 74/132
co
A « OII
I
U I
L UO
CC
cocoL U
ccI—co
F I E L D - W E L D E D R I B J O I N T S O F O R T H O T R O P I C S T E E L . B R I D G E D E C K S
( S - N C u r v e s a c c o r d i n g t o E U R O C O D E 3 )
3 6 0
3 2 0
2 8 0
Sb 2 4 0
Ş 200 M 180
Ü 160 o ai
_ HO
120
100
90
80
70
60
50
40
10
I I I I I I I I I REGRESSION LINES
CONSTANT AMPLITUDE TESTS
T I I I I I I I I 1 I I I I I I -
J U - D E L F T S t e v i n L A B O R A T O R Y S t e e l S T R U C T U R E S
1 ' i i i i i n 4 2 3 4 5 67 9 s
10
T I I I I I I I I 1
V A R I A B L E A M P L I T U D E T E S T S E
F.H.K.-TRAPEZPROFIEL 2/325/6 Fe 51 0 ^
TYPE A : Bult spilet with back-up «trips Z
TUD ECSC-RESEARCH KOLSTEIN 1989
SIMULATED LOADSPECTRA RHEDEN TRAFFIC
* EQUIVALENT
STRESS
USING
SLOPE
3
-A EQUIVALENT STRESS DEFINED BY B R U L S l
— run-out
* -
J 1 ' I I I I I I 2 3 4 5 6 7 9
10
J— 1 l l i i n 3 4 5 6 7 9
J I I I l l i i
10
NUMBER OF CYCLES (UNTIL TOTAL FAILURE)
Figure 4.11 : Field-welded rib joints of orthotroplc stee l bridge decks
3 4 5 6 7 9 R
i o8
[ N ] — - >
STST-006.GRA
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 75/132
F I E L D - W E L D E D RIB J O I N T S OF O R T H O T R O P I C S T E E L B R I D G E D E C K S
( S - N C u r v e s a c c o r d i n g to EUROCODE 3)
/ \ 400 p-I
36 0
32 0
— , 280o
^ 240
r: 200
1
0)
1
<>aoi—
om
_*- tz3Oz
LxJ
O
-z .
a :COCO
180
160
140
120
100
90
80
70
60
Ol
CO50
40
" I — I I I I I I I
LTU-DELFTStevin LABORATORYS t ee l S T R U C T U R E S
I I i i i i i n
1 I—I I I I I I I
\
103 4 5 6 7 9
1 I I I I I Ml 1 i 1 I I I I I ;
C O N S T A N T A M P L I T U D E T E S T S E
TRIANGULAR STIFFENER
TYPE A : ROOT CAP 6 - 12 rrm.
O TRRL-RESEARCH CUNINGHAUE 1982 —
-RESEARCH SANPAOLESI 1989—
— r u n - o u t
J I I I I I I I I
3 4 5 6 7 9-I I I I I I II3 4 5 6 7 9
J I.I I I I I
TACK WELD
3 4 5 6 7 9
1 0 10 1 0 ' 10
N U MB E R OF C Y C L E S (UNT.L TOTAL FAILURE) [N] >
Figure 4.12 : FlelrJ-welded rib Joints of orthotroplc stee l bridge dec ks- Triangular stiff ener
8
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 76/132
O)
co
F I E L D - W E L D E D R I B J O I N T S O F O R T H O T R O P I C S T E E L B R I D G E D E C K S
(S-N Curves according to EUROCODE 3)
/ \ 4 0 0
¡ 3 6 0
I3 2 0
2 8 0
t± 2 4 0
OCL
Z 20 0
I 180
i 160
o-z.«=tQ :
cocoL U
CEh—co
140
120
100 -
90 -
8 0 -
7 0 -
60
50
40
1 I I l i l i l í \ I 1—I I I I I
J U- DE L F TS l e v i n LA BO RA TO RYS t e e l ST R UC T UR E S
1 l ' i i i m
1 I I I I I I I I 1 1 — i | I I l b
C O N S T A N T A M P L I T U D E T E S T S E
TRAP E Z O I D AL STI F F E N E R
P > 1 mm.
TR O U P 1 9 7 4
EARCH HOLSTEIN 1 9 8 9
PAN YAUADA 1 9 8 9
— run-ou I
El
io3 4 5 6 7 9
J 1—I l l l i M
1 03 4 5 6 7 9
J l l i l i l l3 4 5 6 7 9
_L J I I I I I I
1 0 1 03 4 5 6 7 9
1 08
N U M B E R O F C Y C L E S (UNTIL TOTAL FAILURE)
F igu re 4 .13 : F ie ld -w e lded r ib Jo in t s o f o r t ho t ro p ic s te e l b r idge decks[ N ] — - >
S T S T - 0 0 1 . G R A
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 77/132
O)(O
F I E L D - W E L D E D R I B J O I N T S O F O R T H O T R O P I C S T E E L B R I D G E D E C K S
(S - N Curves according to E U R O C O D E 3 )
A 4 0 0IIII
3 6 0
3 2 0
2 8 0
oQ . 24 0
C 200
Î ' 8 0
3 160
£ 140i
* 120
O
en
cocoUJ
I—CO
100
90
80 h
70
60
50
1 I I I I I II
40
1 0
Figure 4
T U - D E LS I ev ¡ nS t e e l S "
I L
"I I I I I I II I 1—I I I I I
C O N S T A N T A M P L I T U D E T E S T S E
TRAP E Z O I D AL STI F F E N E R
: ROOT CAP < 3 mn.
E C S C- R E S E A R CH K O L S TE I N 1 9 8 9 I
EARCH JAPAN YAIIADA 1 9 8 9
— r u n - o u l
I I 1 I II I I I I II4 5 6 7 9
I I I 1 I I I
1 0 1 0 " 1 0
N U M B E R O F C Y C L E S (UNTIL TOTAL FAILURE)
,14 : Field-welded r ib Joints of or thotropic steel br idge decks
2 3 4 5 6 7 9 o
1 0
[ N ] - — >STST-002.GRA
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 78/132
5. CONNECTION STIFFENE R-C ROSSBEA M.
5.1. Types of connection.
Bridges with orthotropic steel decks buil t in Europe used trapezoidal
or 'V' shaped longitudinal st iffeners. Sometimes in the past these longitudinal
st iff en ers were butted up to the transv erse s t iffen ers. Fatigue fai lure of these
troug h to crossbeam welds occu rred in heavily traffick ed bridges in less than
20 years. In other cases, the longitudinal st iffeners passed through cut-outs in
the crossbea ms and the conn ections were no long er w eakened by load carrying
welds at" each side of the crossb eam . Unti l now, no fai lures of the st iffener
through crossbeam connections have been reported, however, information about
the fat igue classificat ion of different types is unknown.
Tests at TRRL were intended to establish the fat igue behaviour of
thr ee connections typica l of the la te r typ es. They are i l lustr ated in Fig. 5.1 .
Recent research [26] suggests an improved form of the cut -outs in the
crossb eam , see type ' R' , Fig. 5.2. Te sts a t D elft were intend ed to get an
agreement of stress distributions and fat igue behaviour of three types of
connections (Fig. 5.2) and not to define a fatigue design curve. The work of
LBF was to study stress fields in the crossbeam in different shapes of
cut-outs in order to reduce stress concentrat ions (Fig. 3.3 and 3.1).
5.2. Stress determination.
5.2.1. Measurements on a deck panel at TRRL.
The three types of connection shown in Fig. 5.1. were incorporated
in the ce nt ra l crossbeam of a 15.2 m long by 3.1 m wide deck paneL Strain
gauges were instal led around each connection, on the web of the trough and
on th e crossb eam , 15 mm. from th e ro ot of th e weld. The main gaug es
instal led around co nnections 'A ' and ' B' are shown in Fig. 5.1 .Stat ic loads were applied to the panel through a single wheel and the
influence surface of stress was obtained for each gauge posit ion.
The panel was unsurfaced.
70 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 79/132
By superposition, longitudinal influence lines of stress were calculated
for the vehicle types described in the British Standard code of practice
for fatigue, BS 5*100 part 10 [11], Using the Rain-flow cycle counting
method, histograms of stress ranges were calculated for one million
vehicles distributed across the deck (BSS^OO, clause C.1.*0 with the
centreline of the distribution directly over the trough. The stress spectra
for the important gauge positions around connections 'A' and ' B' are given
in Table 5.1 •
5.2.2. Measurements on a UK bridge.
Strain gauges were installed around a trough to crossbeam connec
tion on a heavily trafficked UK bridge. The instrumented trough was located
under a slow lane wheel track. Gauges were installed at the positions ofhigh stress indicated in the panel tests (see Fig. 5.1).
Strains were recorded continuously for a two week period during which the
asphalt temperature ranged from -1.6°C to 18.0°C (mean 7.6°C). Stress
histograms for the 8 gauges are given in Table 5.2.
5.2.3. Local stress calculations and measurements in the web of the
crossbeam at LBF.
The stress level in the web near to the cut-outs is proportionalto the shear forces in the crossbeam and is practically independent of
bending moment. Additionally, these stresses are influenced by the loads
introduced locally into the crossbeam. Therefore the fatigue problem at the
two critical points (notches in the cut-outs and end of weld between the
stiffener and the web near to the cut-outs) may be investigated by using a
simply supported crossbeam together with short pieces of the stiffeners and
of the deck plate as a test specimen and as a model for calculation (Fig.
5.15). This crossbeam model may be loaded by definited shear forces to
simulate stress distributions and stress time histories similar to those in
bridges under real load conditions.
Two shapes of cut-outs in the web of crossbeams were investigated,
one which is commonly used (type II) and the other, an "improved" design
proposed by Haibach [26] after investigating crossbeams of railway bridges
(type I ) . The stresses due to shear forces in the beams at both types of
cut-outs were computed and measured, Fig. 5.3, 5.4, 5.5.
As a result the stress distribution around the cut-outs was found to be
antimetrie with respect to their plans of symmetry. The level of maximum
stress at the notches of both cut-outs is nearly the same but the volume of
highly.
- 71 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 80/132
stressed material is much larger in the conventional cut-o uts. At the end
of the welds (the other critical point of the connections) the new shape
produces significantly lower stresses than the conventional shape.
5.2.^. Stress Spectra.
The stress spectra were obtained using the simulation program of
the University of Lièg e. This program calculates the level crossing and the
Rain-flow histograms.
Two influence lines are tested with the Rheden traffic :
* influence line concerning stresses due to bending moment at the
stiffener on the support of a continuous beam. This has been
measured by the T.R.R.L (Fig. 5.6. and table 5. 5) .
* influence line of the support reaction of a continuous beam. This
has been given by the L.B.F. (Fig. 5.7.).
5.3. Test results of TRRL.
5.3.1. Test specimens.
Full-scale test specimens were manufactured comprising a 1500 mm
length of deck plate, a single trough and a central crossbeam. Two types of
specimen were made with the detailing of the trough to crossbeam connection
representing the 'A' and ' B' connections of Fig. 5.1. Six millimetre,
single pass, Manual Metal Arc Welds were used for the trough to crossbeam
connection. Inspection of the welds showed them to be representative of
those that could be found on a typical bridg e. The specimens were loaded in
a reaction frame test rig, illustrated in Fig. 5.8.
Strain gauges were installed at the high stress locations around
the weld (and 15 mm from the wel root) in identical positions to the gauges
on the test panel. The loading on the specimens was arranged to produce a
similar distribution of stress around the connection as that determined
from the tests on the deck panel with the wheel load in the most damaging
position.
- 72
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 81/132
Five type 'A' and six type 'B' specimens were tested at constant
amplitude. A further four type ' B' specimens were tested at variable
amplitude. In all cases a 25 mm crack was defined as failure of that part
of the specimen.
5.3-2. Test results - type 'A' connection.
Fatigue cracks developed at four locations (see Fig. 5.9), though
not necessarily all in the same specimen :
crack a was a weld toe failure through the trough plate at the bottom of
the weld, initiating within 25 mm of the weld end. This crack was expected
from the high stresses found at this point in the panel tests.
Crack b was in the crossbeam plate at the bottom of the weld.
Crack c was in the trough plate at the top of the weld. It occurred in all
5 specimens, on both sides of the trough and on both sides of the cross
beam. In all cases cracks initiated at very low endurances. Stresses were
found to be much higher at this location than had been expected ; the
stresses were confirmed by measurements on the panel.
Crack d was in the crossbeam plate at the top of the weld. It occured in
only three specimens and at much longer endurances than crack c. It is
regarded as a secondary order crack.
For cracks a, b and c the endurances for a 25 mm crack are given in table
5.3 and plotted in Figure. 5.10, against the stress measured by the strain
gauge adjacent to the crack location. Estimated stresses at crack b were
used for four of the specimens. The data are compared with Eurocode S-N
curves. It is concluded that class 50 is appropriate for the failure in the
trough plate at the top of the weld (crack c) and class 125 for the weld
toe failure at the bottom of the weld (crack a ) . A high classification is
indicated for crack b from the estimated stresses at this point.
5.3.3. Test results - type '3' connection.
Out of six specimens, the two tested at the lowest stresses (95
and 100 N/mm2) were uncracked after 11,7 and 13,2 million cycles respecti
vely. The remaining four specimens all suffered weld toe failures through
the trough plate as expected (see Fig. 5.8.). Cracks initiated near the
apex of the trough. In one specimen, a second crack developed in the toe of
the weld at the crossbeam.
73
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 82/132
The endurance for a 25 mm crack is given in table 5.1 and is
plotted in Fig. 5.11. against the stress in the trough plate (at the apex
of the trough) adjacent to the weld. The results indicate a weld class 80.
Four specimens were tested under variable amplitude loading. The
applied stress spectrum was derived from the static load test data (section
5.2.1) for the gauge on the apex of the trough under the vehicle loading
from the Rheden Bridge (Section 5.2.1). The level of the spectrum was
raised to obtain failures in a reasonable timescale. The spectrum used in
the tests if given in Table 5.5.. It has an equivalent stress range La of
97.1 N/mm2.
1/3where Ao - [(1/Zn.) x E(n. a.')]
e i i i
The results of the variable amplitude tests are also shown in Fig. 5.11.»
plotted at the level of the equivalent stress range. The four results are
below the mean line of the constant amplitude tests the average endurance
suggesting that a fatigue life based on the Palmgren-Miner summation would
be optimistic by a factor of about 2. However, three out of the four
results are within the 95 % confidence limits for weld class 80.
5.3.1. Fatigue life calculations.
For each type of specimen, strain gauges were installed in identical positions on the deck panel and on the fatigue test specimens. It is
therefore possible, using the stress spectra calculated from the static
tests on the deck panel (Table 5.1.) and the weld classifications determi
ned from the constant amplitude fatigue tests, for corresponding gauges, to
calculate the fatigue lives of the connections for BS5100 traffic loading :
Type 'A' - crack a, bottom of weld through trough - > 120 years
- crack b, bottom of weld through crossbeam - > 120 years
- crack c, top of weld through trough - 5 years.
Type ' B' - crack through trough plate at apex of trough - 13 years.
The lives quoted are for a 2,3 % probability of failure and for
one million HGVs per annum. There is no influence from bridge deck
surfacing in these calculations.
Lives were also calculated using the stress spectrum obtained from
the measurements on the bridge. For crack c the life is calculated to be
280 years. This assumes that the traffic flow across the bridge and thetemperature of the bridge deck surfacing for the two week measurement
period is typical of that throughout the year. In fact the traffic flow is
- 74 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 83/132
k now n to be only about half a million HG V s and the su rfacing temperature
was below the annual mean.
Consequ ently, the connectio n fails to meet the U K design re qu irements
though failures in service are not expected to occur within the lifetime
(120 years) of the bridge.
The fatigu e life of 13 years calcu lated for the type '3 ' connectio n from
the constant amplitude tests would be reduced to around 6 years using the
average endurance data from the variable amplitude tests.
5.H. Tests results of the T.U. Delft.
Two series of tests were executed. In the first series the fatigue
load was about 50 % higher than in a real bridge. In all cases no cracks
w ere fou nd after testing for at least 12 milli ons cycle s. I n the second
seri es of tests the specime n of the first series w ere cu t in to tw o piec es
and were tested at a much higher level (at least H times the first loading
case). The testrig in that case was the same as used by the Transport and
Road Research Laboratory.
5.^.1. Test specimens.
The specimens for the bending tests of the first series were
single rib specimens. The ribs were rolled trapézoïdal sections of steelg rade F e 5 10 . The dimensions of the cross secti on w ere equal to a F .K .H . -
Trapezprofile nr. 2/325/6. As the usual spacing of the ribs is 600 mm., the
w idth of the deck plate in the specimens w as also 6 0 0 mm., in order to g et
the same position of the neutral axis as in an actual bridge deck. Three
types of specimen were made with the detailing of the trough to crossbeam
connection representing the ' S' , •T' and ' R' connections of figure 5.2.
These connections w ere manu ally w elded. B y cu tting the test specimen in
two pieces the specimens of the second series were made in the same rig as
used at TRR L (Fig. 5 .8 ).
The first test series were executed with loading equipment from
Losenhau ser. The second series were carried out u sing serv o hydraulic test
equipment operating in closed loop control with load feedback.
- 75
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 84/132
Each test specimen was instrumented with a number of strain gauges
before testing. Strain measurements were carried out dynamically for 2k
hours a day to obtain information about the time and location of crack
initiation.
Measurements of crack growth were carried out during a number of
the tests. This was done by periodic visual inspection with a magnifying
glass. It was only possible to measure crack length at the surface of the
specimens.
Where possible, four stages of fatigue failure are expressed
(see section 4.M.2) :
5.1.2. First series of tests.
As mentioned before no cracks were found in the first series of
tests at a load range of 50 kN. From these results it appears that the
highest stress is measured in the connections without cut-outs. The
stresses measured on the connections with the new design of the cut-outs
are a little bit higher than the design with the old cut-outs.
5.^.3. Second series of tests.
A review of the test results is given in Table 5.6. In this table
the following parameters are given :
- the fatigue load ;
- number of cycles for each stage of fatigue failure in the crossbeam and
the weld.
The results plotted on Fig. 5.13 and 5.1*4 correspond to N3.
The location of the cracks is shown in Fig. 5.12.
The cracks appeared in the crossbeam are influenced by the test specimen
and the testing, they are not considered her e.
The two specimens type ' S' suffered weld toe failures through the
trough plate as expected. Cracks initiated near the rounding of the
botton-web of the trough. Fig. 5.13 shows that the fatigue behaviour is
better than the highest class of the Eurocode curves.
- 76 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 85/132
In type 'T1 - connection, fatigue cracks developed in the
crossbeam in the rounding of the cut-out and the weld toe through the tough
plate at the botton of the weld. For the crack initiating at the weld, the
endurance is plotted against the stress measured at 12 mm from the weld toe
(Fig. 5.11).
Just as the type ' T' - connection, in type ' R' connection, fatigue
cracks developed in the crossbeam in the rounding of the cut-out and at the
weld toe through the trough plate at the bottom of the weld. For the crack
initiating at the weld, the endurance is plotted against the stress
measured at 12 mm from the weld toe (figure 5.11). It seems that also
fatigue behaviour of this detail is a little better as for connection T.
5.1.5 Conlusions.
Connection type S, without cut-outs has a better fatigue behaviour
as connections type T and R with cut-outs. The fatigue behaviour of
connections type T and R is very near. This conclusions are in opposite of
the results obtained at the V stiffeners (section 5.3) : type B, without
cut-outs gives a fatigue behaviour near at type T and R, but type A, with
cut outs at the apex, gives a higher fatigue behaviour as type B.
5.5. Test results of the L.B.F.
5.5.1. Test conditions.
Three test specimens were fabricated, nearly the same scale as the
orthotropic decks of real bridges, each consisting of a cross beam, 6
stiffeners, and a deck plate. One of the specimens had cut-outs of the
commonly used shape and two the improved shape . When the specimens are
loaded as shown in Fig. 5.15, four of the cut-outs are stressed at nearly
- 77 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 86/132
the same level. This is due to symmetry and the constant shear force.
Therefore up to four results can be expected from each test specimen,
provided cracks are early detected early and repaired.
Three fatigue tests were performed one with constant amplitudeloads applied to a specimen with the new shape of cut-outs and two using
identical load sequences of variable amplitude (derived from measured
traffic loads) applied to the other two specimens one with the old and one
with the new cu t-ou ts.
5.5.2. Test results.
Test results are given in Fig. 5.16, 5.17, 5.18 and 5.19 cracks
occured at both critical points of the connection specified earlier. Atthe end of the welds between the longitudinal stiffeners and the
crossbeam, cracks were observed only in the specimens with the new shape
of the cut-outs, althoug h this shape was developed especially to reduce
the stresses at this point. The stresses due to the external loads are
actually lower as shown by computation and measurement, Fig. 5.3, 5.4.
H ow ev er, it seems that the new shape increases residual stresses at the
end of the welds due to unequal heating during welding. High residual
stresses allow fatigue cracks to develop ever when the stresses from the
applied loads are low. With crack initiation, the residual stresses are
removed and the craks do not grow (this was observed during the tests).
In contrast the cracks initiated at the notches of the cut-outs
grew and would have destroyed the specimens if not repaired. These cracks
occured at the cut-outs of the new shape after 3-5 times more load cycles
than at the more commonly used cut-outs, which means a significant
improvement of fatigue life.
However high residual stresses globally distributed in all three specimens
were observed without any doubt. Their influence on fatigu e is so strong
that cracks occured at notches stressed only in compression due to the
external loads, while other notches remained crack free, although stressed
in tension at the same level. Therefore it is not clear, whether the
increase of life time is due to the new shape of the cut-outs alone or at
t least partially to a more favourable residual stress distribution.t
v . /78 -
i
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 87/132
5.6. Conclusions.
Three types of stiffener to crossbeam connection were tested at
TRRL, LBF and Delft : welded all round and with conventional and 'impro
ved' cut-outs in the crossbeam around the apex of the stiffener. Both
trapezoidal and 'V' shaped stiffeners were tested. In one of the research
programmes the main aim was to study the fatigue behaviour of the
crossbeam by applying loads to produce shear forces in the cross beam. In
the other two programmes the fatigue behaviour of the welds was studied by
applying bending stresses to the longitudinal stiffener.
Despite difference in the shape of the longitudinal stiffeners,
the weld sizes and probably different residual stresses due to different
weld procedures, a minimum weld classification of class 80 followingEurocode 3 can be considered for the welded all round connection. However,
a higher classification may be considered for connection type S
(trapézoïdal stiffener without cut outs) as for connection type A
(triangular stiffener with cut-outs at the apex). Conclusions for joints
in trapézoïdal stiffener are provisional, because only results for two
tests for each type of connection are available.
Most of the variable amplitude test on this type of connection
gave a good agreement with the constant amplitude tests applying Miner's
method of damage summation.
Because of the difference modes of failure from the difference
types of welded connections with cut-outs in the crossbeam it is not
possible at present to define an overall classification for this detail.
For specific details, classifications are given in previous sections where
possible.
The improved form of cut-outs did not result in a better fatiguebehaviour as had been expected. Cracks occured in unexpected locations in
the crossbeam connection in the new design despite low calculated stresses
at this point. Weld toe failures occurred at similar endurances in the
conventional design. For the failure in the crossbeam plate the new design
was an improvement over the conventional design but it was difficult to
manufacture this shape of cut-out without producing notches.
79
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 88/132
For the 'V* shaped stiffeners, the connection with cut-outs
behaved better than the fully welded type. This was not the case with the
trapezoidal stiffeners. A possible explanation is that residual stresses
may be higher at the apex of the 'V' stiffener than in the bottom of the
trapezoidal stiffener. Therefore a cut-out at the apex of the stiffener
which avoids residual stresses in this area gives a greater improvement in
fatigue behaviour for the 'V' stiffener.
To give a general classification for stiffener to crossbeam
connections it would be necessary to refer to nominal stresses rather than
stresses at specific points which cannot be easily calculated by the
designer. Further analysis of the results and additional research is
needed to give practical design 'recommendations.
- 80 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 89/132
09
STRESS
RANGE
°R(N/mm2)
0-10
10-20
20-30
30-40
40-50
50-60
60-70
70-80
80-90
90-100
NUMBER OF CYCLES
CONNECTION 'A'
GAUGE 13
6477245
481807
355667
255613
83593
22933
4063
0
0
0
CONNECTION 'A1
GAUGE 88
6118059
718470
279695
317424
175765
61490
38862
3899
0
0
CONNECTION 'A1
GAUGE 90
8456885
520645
288755
100389
0
0
0
0
0
0
CONNECTION 'B'
GAUGE 49
3119612
1254028
582721
302745
146634
205557
78214
21212
11404
1969
- For 1.000.000 HGVs
Centre of distribution of vehicles over centreline of trough
TABLE 5 . 1. S T R E S S E S F R O M T E S T S O N D E C K P A N E L
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 90/132
1
00r oi
STRESS
RANGE
°R(N/mm2)
8-12
12-16
16-20
20-24
24-28
28-32
32-36
36-40
40-44
44-48
48-52
52-56
56-60
1
15383
4614
1790
876
455
229
80
21
5
0
0
0
0
2
14680
10408
6254
3515
2116
1698
1082
490
177
42
4
1
1
3
20851
11301
5613
2236
992
325
34
3
0
0
2
0
0
NUMBER OF CYCLES
GAUGE NUMBER
4 5
17866
11785
3642
747
227
29
0
0
0
0
0
0
0
14454
5038
2071
1153
682
438
330
157
60
15
2
1
0
6
16098
10518
6064
3535
2569
1600
537
127
21
9
1
2
0
7
26099
12632
. 6787
2650
1463
664
186
28
2
1
0
0
0
8
20709
16227
10108
3341
936
518
120
17
0
0
0
0
0
TABLE 5 . 2 . S T R E S S E S F R O M M E A S U R E M E N T S O N B R I D G E
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 91/132
00
u
SPECIMENNUMBER
IA
2 A
3 A
5 A
8 A
CRACK a
NORTH SIDE
STRESSRANGE
O i
(N/mma)
12 5
I S O
2 0 0
14 4
16 0
CYCLES
TOFAILURE
X 1 0 d
>12.4
5 .2
1.8
1.4
6.3
SOUTH SIDE
STRESS
RANGEo=,(N/mmz)
11 3
14 2
19 2
17 5
15 1
CYCLES
TOFAILURE
X I O *
)12.4
> 6.3
> 2.5
2 .1
> 7.0
CRACK b
NORTH SIDE
STRESS
RANGE
(N/mm3)
1 3 7 -
1 6 4 *
2 1 9 -
1 5 8 -
17 6
CYCLES
TOFAILURE
X 1 0 &
>12.4
> 6.3
2 .3
2 .1
> 7.0
SOUTH SIDE
STRESS
RANGEOii»
(N/mmz)
1 2 4 -
1 5 0 -
2 1 0 *
1 9 2 *
17 7
CYCLES
TOFAILURE
xio<-
>12.4
5 .8
> 2.5
1.8
> 7.0
CRACK c
NORTH SIDE
STRESS
RANGEOT »
(N/ram=)
3 9 *
4 7
7 3
5 6
6 3
CYCLES
TOFAILURE
X I O *
6.3
3 .0
1.8
2 . 7 "
2 .9
SOUTH SIDE
STRESS
RANGEO n(N/mm*)
5 0 -
5 9
6 3
5 4
6 3
CYCLES
TOFAILURE
X I O *
8 .2
4 .0
2 .4
2 . 9 "
5 .2
denotes estimated stressdenotes extrapolated cycles
TADLE g-3 FATIGUE TEST RESULTS - TYPE 'A' SPECIMENS T.R.R.L
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 92/132
SPECIMENNUMBER
233343637B8B
STRESSRANGE
Ca(N/RWli*)
95150125115100200
CYCLESTO
FAILUREX10*
>11.700.902.801.67
>13.200.47
a) SPECIMENS TESTED AT CONSTANT AMPLITUDE
SPECIMENNUMBER
10312B13314B
MAXIMUMSTRESSRANGE
O i
(N/rem3)
245245245245
CYCLESTO
FAILUREXI0*
2.120.7S1.862.75
b) SPECIMENS TESTED AT VARIABLE AMPLITUDE
TABLE SA FATIGUE TEST RESULTS - TYPE -'B ' SPECIMENS TRRL
- 84
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 93/132
STRESSRANGEN/mro2
CLASSCENTREN / i r a n
2
CYCLESni
50-60
60-70
70-80
80-90
90-100
100-110110-120
120-130
130-140
140-150
150-160
160-170
170-180
180-190
190-200
200-210
210-220
220-230
230-140
240-250
55
65
75
85
95
105115
125
135
145
155
165
175
185195
205
215
225
235
245
23710
17440
12590
10920
9080
68505290
3440
3690
2340
"980
1410
570
710340
90
240
70
50
10
TABLE 5. 5 S T R E S S S P E C T R U M U S E D
I N T H E T R R L T E S T S "T&ft-l
- 85
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 94/132
TESTSPECIMEN
TYPE
v v y \ J
u
\j
\j
NR
SI
S2
R2
Rl
TI
T2
LOAD
[kN]
200
200
200
267
266
267 ■
LOCATION OF
CRACKS
VELD
CROSS BEAM
VELD
CROSS BEAM
WELD
CROSS BEAM
VELD
CROSS BEAM
VELD
CROSS BEAM
VELD
CROSS
BEAM
NORTH SOUTH
NORTH SOUTH
NORTH SOUTH
NORTH SOUTH
NORTH SOUTH
NORTH SOUTH BOTTOM
NORTH SOUTH
NORTH SOUTH
BOTTOM
NORTH SOUTH
NORTH SOUTH
NORTH SOUTH
NORTH
SOUTH
NUMBER OF CYCLES (xlOE06)
Nl
0.080
0.660
0.090
0.480
0.040
0.016 0.016
0.050
0.100
N2
1.658
0.809
1.157
1.125
0.271
0.771 0.174 0.653.
0.241
0.025
0.025
0.087
0.187
0.208
0.103
0.175
0.369
0.084
N3
1.732
0.879
1.184
1.157
0.474
1.190
0.711
0.250
0.564
0.087
0.112
0.348
0.606
0.397
0.351
0.676
0.376
N4
2.461
2.461
1.272
1.272
1.190 1.190
1.190
1.190
1.19P
0.572
0.572
0.572 0.572 0.572
0.700
0.700
0.700
0.700
0.856
0.856
0.856
0.856
Nl : Moment of crack initiation by 10 X strain fall of, measured in the
strain gauge nearest to the crack.
N2 : Moment of visuable crack initiation.
N3 : A crack indicating the number of cycles when a surface crack length
of ± 50 mm is reached.
N4 : End of extensive through cross section cracking.
Tablé S.'£.. Review of the second series results. T.U. Delft.
86 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 95/132
Type 'A'
Deck plate
00
Type 'C'
Type 'B'
Web of t roughWelded connect ion under test
and weld
Icul oul )
Figure 5 .1 : Types o f long i tud in a l / t ran sve rse s t i f f en er connect lon-TRRLAnd main gauges in test (specimen 'A'and 'B'and in the bridgestudied (specimen 'C'
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 96/132
00
co
and weld(cut out)
Figure 5.2 : Types of longitudinal / Tramsverse stlf fen er connection
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 97/132
00(O
load F = 200kNs. Fig. 5.21)
• measured at ~ 2 mmdistance to the edge
D measured on the edge
b^
calculated
Figure 5.3
COMPARISON OF COMPUTED AND MEASURED STRESSES AT THE CUT-OUTS OF THE NOW USUALLYUSED SHAPE (TYPE II)
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 98/132
o
%
c.
calculated ^
/S
/
CO I \
- c o m pression
\ \
X
xmeasured at - 2 mmdistance to the edge
load F = 200kNI s . Fig. 5.21 J
Figure 5.4
calculated
DD
\D
measured onthe edge
mea sured at ~ 2 mmdistance to the edge
COMPARISON OF COMPUTED AND MEASURED STRESSES AT THE CUT-OUTS OF THE SHAPEPROPOSED TO BE BETTER {TYPE I)
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 99/132
(O
measuredst ress
Figure 5.5
STRESS DISTRIBUTION IN THE NARROWST SECTION BETWEEN THE CUT-OUTS OF THE SHAPEPROPOSED TO BE BETTER
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 100/132
2 0 -
15 ■■
10 ■■
5 "
I 76.21
(152.AI
(226.6)
(30 4.81
___. influence line
/ V - " XN . used for —»
//' ^, the simulation./^' ' • ^ .
/ v f/r^X w (381.0) v \ a/ /
%
\ \
/
\ if
\\W/ m i /
. 1 /
-H 1 1—I—' I I i \ W / / l 1 I I h—I—I—I—I—I—I—h
:\':I/-K A1 M CO K7 75 3 7 11 15 19 25 \W/3S « 51 59
67 75 y ■■ fop a 20kN wheel W
3 -
"N/mm2 i n f luence l ines measu red at the T.R.R.L. wi th a 20kN whee l
Histogram Rain f low NI/NTOT
cu--
0.3 - •
0.2-■
0 . 1 - -
Rheden Traffic
' rT") n 11111111 N/mm H — » -
50 100 150 20 0 250
Fatigue damge , .D I
10 + 9
8 ■•
7 - -
E
5
4 -
3 -
2 -
1 ■
r£
E k 150
D3 1/0.SE*03
nDz0.3A2n3o
_DL N/mm'
-4-50 100 A S
20 0 250
Figure 5.6 : De ta i l t e s t e d at T.R.R.L.
92 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 101/132
Inf luence line
0. 5 -■
Histogram Rain f low
NI /NTOT
Rheden Traf f i c
0. 4 -■
0. 3 - •
0.2 - •
0. 1 - •
100 20 0 300 ¿00
kN
500
Fatigue damge M D I
1 0 - •
g . .
8 - -
7 ■ -
6 - -
S ■ -
¿ - -
3 ■ -
2 -■
1 ■-
=d£ i L
D3 1 / 0 . 1E .0 5
n m =0.108 na j ,
UL . kN - H ■ -SOO 00 20 0 3 00 ¿0 0
Figure 5.7 : Detai l t es ted at LBF
93
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 102/132
Hydraulic actuator
Reaction frame
Figu e 5.8 : Fatigue t e s t rig
94
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 103/132
Soirth si d«
TYPE A SPECIMEN
South si dì
Fatigue crack at toe of velo
Figure 5.9 : Location o f cr ack s in fat ig ue t e s t specimens
95
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 104/132
lOÜO
STRESS RANGE N/mm 2
(O O)
100
Mean line 9Ş% confidence Limirs
o crack a • crack b x crack c
Eurocode class 125
Eurocode class 50
J l i l i
CYCLES I U '
Figure 5.10 : Fatigue t e s t s a t cons tan t ampli tude - TYPE A* SPECIMtNS
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 105/132
CO
1000'
3 0 0 -
HANGE
( l l / mm a )
1 0 0
50
10-
APPLJED «IMÍCTUWM
"1 1 1 1" I i l l
Ş-ÎLii'Unviîş rem
Evnocohiz cLÃãs 'uu
i 1—i—i—i i i i
[-lean l i n e
V57. c o n f i d e n c e 1 imi LK
Test::» a t c o n f i a n t . ;>mi> I. ¡ L u d e T e s i s a t v a r i a b l e amp i I U n i e
10
C YC LES
Figure 5.11 : Tests on TYPE B SPECIMEN
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 106/132
TYPE S
Crack
TYPE T
Erack
TYPE R
Crack
Figure 5.12 : Location of the cracks
in the fat igue tests specimens
- 98
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 107/132
TROUGH TO CROSSBEAM CONNECTION OF ORTHOTROPIC STEEL BRIDGE DECK
CO CO
i o c -7
ro
° -H m «^f ro -•-
OJ » O
<D <">
■ a n> ro o
S'Y1
*~ I
ro a f ro<" .— i - h -J
-*■ CU 3 UD CD
A
I
I
n.
< o j CD
(/) V) O f t U
2 O K
m
Lu
O
z: <
co co IJ J
ce i—
co
400
360
320
280
240
200
180
160
140
120
100 -
90
80
70
60
50
(S-N Curves according lo EUROCODE 3)
1— r I I I I I I I T "I—I I I I I II
40
i i— i i 11 i i 1—i—n-rrru CONSTANT AMPLITUDE TESTS E
THEORETICAL NOMINAL STRESS RANGE -
TUD-ECSC Resea r ch
•. TYPE - T : Con n e c t i o n w i t h ' o l d * c u t - o u t «
A TYPE -R: Con n e c t i o n w i t h 'new' c u t - o u t «
C O í ^ 5 C O ô T Y P E - S : Con n e c t i o n w i t h o u t c u t - o u t «
TU -DELFT S t e v i n LABORATORY S t e e l STRUCTURES
I l I l l LLU i.
— r u n - o u t
3
10 3 4 5 6 7 9
J I I I I I II .J I I I I I I I J l_.L
3 4 5 67 9 _U±
10 10 3 4 5 6 7 9 7
10 3 4 5 67 9
10
NUMBER OF CYCLES (AT VISUAL CRACK INITIATION) [N ] CRB.GRA
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 108/132
o o
UD
c ro u i ~ & ■p-
- f o
s« QJ UD
UD -* •
ro < " - * ■
50
ro
A
o.
UJ
o
iÜ
3 T ro
- s w -J c o «—
s ir
,?-> TD
£ M
a" 1. O ^ ro Q -
o K. u.
> ■ij
fM
*m^
LÜ
<J )
-z .
er C O C O Ld
o : r -co
TROUGH TO CROSSBEAM CONNECTION OF ORTHOTROPIC STEEL BRIDGE DECKS
400
360
320
28 0
24 0
20 0
18 0
16 0
140
12 0
10 0
90
80
70
60
50
40
( S - N Cu r v e s a c c o r d i n g t o EUROCODE 3 )
i n - n r m 1—i—r-rrnr
= wel
//////////s.
12
'Ao
JU-DELFT S t e v i n LABORATORY S t e e l STRUCTURES
I l l I I LLLL
"i i r~i i 11 n i — t — i - i n r n T CONSTANT.AMPLITUDE TESTS E
LOAD RANGE 2 00 - 26 8 KN
TUD-ECSC Resea r ch
U TYPE -T : Con n e c t i o n w l l h ' o l d ' e u t - o u t i
A TYPE -R: Con n e c t i o n w i t h ' n ow ' cu t—out»
-•»run—oul
3 4 5 6 7 9 J I I
10 • 1 0
NUMBER OF CYCLES
3 4 5 6 7 9 J I I I I I I I I 2 3 4 5 6 7 9
J _ J _ _ L . L J JX l
1 0 10
(A T A CRACK LCNGTH OF 50 MM)
2 3 4 5 6 7 9 o 10
[N ] >
CRU-12 .GRA
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 109/132
en
u u
QLU
e noÜ_
e nLUCL
LO
LO
dl
DI
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 110/132
load
oto
crack no. 1 after 205 000 cyclescrack no. 2 after 339 000 cyclescrack no. 3 after 339 000 cycles (no crack growth observed )crack no. U after 3 U 000 cyclescrack no. 5 after 350 000 cyclescrack no. 6 after 350 000 cyclescrack no. 7 after 350 000 cycles
T : region with tension stressesC : region with compression stresses
Figure 5.16 : RESULTS OF CONSTANT LOAD AMPLITUDE TEST WITH A SPECIMENHAVING CUT-OUTS OF THE SHAPE PROPOSED TO BE BETTER (TYPE I )
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 111/132
load
oco
crack no.crack no.crack no.
crack no.e n d of test
afterafterafter
afterafter
2 8U 2003 ¿09 900¿ 5¿1 000
5 780 3005 926 600
cyclescyclescycles
cyclescycles
T : reg ion wi th tension s t ress esC : reg ion wi th compression st resses
Figure 5.17 RESULTS OF THE VARIABLE LOAD AMPLITUDE TEST WITH THE SPECIMENHAVING CUT-OUTS OF THE NOW USUALLY USED SHAPE (TY PE I I )
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 112/132
load
o
crac k no. 1 after 6 728 000 cyclescrack no. 2 a f te r 6 728 000 cyc les (no crack growth obse rved)crack no. 3 a f te r 6 728 000 cyc les (no crack growth obs erved)crack no. U af ter 6 728 000 cyc les (no crack growth obser ved)crack no. 5 a f te r 13 385 000 cyc les (no crack growth ob serve d)crac k no. 6 after 16 089 000 cycle send of test after 22 129 000 cyc les
T : reg ion wi th tension s t resse sC : reg ion wi th compression st resses
Figure 5.18 RESULTS OF THE VARIABLE LOAD AMPLITUDE TEST WITH A SPECIMENHAVING CUT-OUTS OF THE SHAPE PROPOSED TO BE BETTER (TYP E I )
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 113/132
oUI
8 0 0
kN
¿ 8 5
¿ 0 0
-ooo
enca
200
100
I I I I I l i l i
S-N t es t resu l t sP = 500 kN
15 kNu=
U c r a c k s
equ iva len t l oad
E n , A P MA P K =
Un, A Pi"
e s t i m a t e d S - N c u r v eslop e k = 5
I I i I U l l 1 — T
resu l t s o f va r iab lea m p l i t u d e t e s t s
Pmax = 500 kNP.. = 15 kN
l i l i l í
B-¿-¿ - E ¿
e-
k = 5k = A
-E¿-k = 3
equ iva len t l oad cyc les
E n , A P :k
i *- ' i
E A R '
1— I I I H i l l 1 — ' ' ' m i i i i i i M M I i i i i i n n10 4 2 3 4 56 8 1 0 5 2 3 4 56 8 1Q 6 2 3 4 56 8 1Q 7 2 3 4 56 8 i n 8
10 (
c y c l e s
Figure 5.19 : RESULTS OF THE CONSTANT AND VAR IABLE LOAD AMPLITUDE TE STS (TYPE I)
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 114/132
6 . O R T H O T R O P I C D E CK T O CR O S S B E A M C O N N E CTI O N .
6.1. Introduction.
The bolted connections tested are used to attach orthotropic deck
plates to supporting I section crossbeams. This type of construction isfound in harbow arens where the bridges carry both road and rail traffic.
These orthotropic steel decks have to be dismountable.
These bolted connections are subjected to complex forces resulting
from angular rotation of the supports (lever effect), from vertical forces
(tension or compression) and from horizontal strains (axial shortening).
These forces are difficult to calculate because they depend on element
stiffness and secondary effects.
Tests were carried out on different specimen configurations
subjected to forces representing those found in bridges.
In addition, tension-bending tests on bolts were carried out.
6.2. Results from the University of Liège on the connection.
The problem was solved using two approaches :
* introduction of fexible elements to reduce secondary bending
stresses.
Tests gave the solution presented in Fig. 6.1. ;
* using elements with sufficient stiffness to reduce secondary
effects.
6.3. Results of fatigue tests on 8.8 bolts.
These tests were carried to study the influence of the following
parameters on the fatigue strength of the bolts :
* stiffness of the beams with influences the angular rotation of bolt
heads and thus influences the bending stresses in the bolts ;
* prestressing ;
* introduction of neoprene element ;
Characteristics of tested bolts are :
* nominal diameter : 12 mm ;
* measured net section : 8*4,3 ram2
* measured ultimate stress : 896 N/mm 2
* Brunell hardness : 280 to 295.
- 106 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 115/132
Test beams are :
* series 1 : IPE 160 - without prestressing.
* series 2 : IPE 160 - with prestressing.
* series 3 : IPE 160 - with neoprene and steel element.
* series H : HEM 120 - without prestressing.
* series 5 : HEM 120 - with prestressing.
A specimen of series k is shown in Fig. 6.2. and test results are
presented in Fig. 6.3»
Prestressing has favourable effects of reducing the angular
rotation and the stress variation.
Figure 6.3. shows that the Eurocode 3 classification is
conservative. It is lower than the most unfavourable tests (flexible
beams without prestressing).
Before to have general conclusion, more test are necessary.
- 107
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 116/132
o00
-Ó
]max :80kN
Q min : 5 kN
1363
Figure 6.1
Coupe. A A
pla t20 5
12
-m a smaamaa t
raidisseur
L_ 100/100/10
rondel leneoprene frette 6Q/3Q/7
ctìT\ neoprene frette 80/80/7
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 117/132
t
70mm
rondel le d'acier 024
i »
♦
rondel le d'acier#24 ep 2mm
point de rupture du boulon
Figure 6.2
109
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 118/132
Boulon 8.8-012
400
32 0
— 2 8 0Cu
CL 2 4 0
CO
2 00
Ü JCD
ŒÛC
COCOU J
enh -m
i 60
mo
12 0
10 0
80
70
60
5 0 -
40
10
I i I I I 1 1 1 I T T
Í.DX
5A
i i i M m I 1 I I I I I I
T T
X5B
SC
AC• • •—*-
3A 3D
3C
t B
2A
3 4 5 6 8 3 4 5 6 8
Figure 6.3
i i i i i i n I i i i i i m3 4 5 6 8 2 3 4 5 6 8
1 pr ofi lé IPE 160
3 prof i lés IPE 160»néoprène
4 prof i lés HEM 120
2 profi lés IPE ICO -p r e s t r e s s e d b o l d .5 pr o fi ls HEM 120 -
N.B. : for s er ie s 2 and 5d rawn s t r e s s r an g esa re n o t a c tu a l s b u tare obta ined as ifbolts where notp r e s s t r e s s e d .
10CYCLES N
10
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 119/132
7 . APPLICATIONS.
The sponsors of this research are the European Community for Cool
and Steel, the National Autorities responsible for bridge building and
bridge builders.
All the results obtained in the laboratories participating to the research
have been widely disseminated in each country . Some of the information is
already used in the new versions of the design rules and national
recommandât ions.
The fatigue strength of the connection stiffener-plate given in
the Belgian Standard NBN 5 has been changed, taking in account the new
results. The experts busy with the redaction of Eurocode 3, have also
been informed of the new results.
The conclusions of chapter 3, concerning the minimum value of the
root gap of the connection stiffener-stiffener is now a rule for the bridge
builders in Netherlands, Italy and France. Designer welder and superviser
are informed, and pay particular attention to this very important detail.
In Germany, the new shape of the cut-outs in the web of the
cross-beam is a part of the design rules of Deutsche Bundesbahn following
the investigations of Haibach and Plasil [2 6]. The research gives
informations concerning the fatigue behaviour of this shape in roadbridges.
Orthotropic decks are excluded form the UK bridges design code
[11] but the code advises the designer to seek specialist advice. That
advice is frequently provided by the TRRL, so that the results of research
are passed on directly to bridge designers. In addition, designs are
subject to technical approval by the Department of Transport who receive
report of all TRRL research.
The results have already been applied in some bridges in
construction.
The new automatic welding procedures studied by IRSID and LCPC for
the connection stiffener-plate have been applied to the fabrication of the
orthotropic steel deck of two large bridges in France :
Pont de Cheviré on the Loire river :
Pont de Normandie on the Seine rive.
Submerged arc welding was used, without edge preparation and the
lack of penetration below 1 mm.
- 111 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 120/132
Analytical methods developed enable the stress range in the
stiffener-plate, weld to be calculated for various stiffener shapes.
Following this calculation, the shape of the stiffener was changed in the
design of the Kruiskansburg in Antwerpen (reducing of the thickness of the
stiffenerweb and increasing of the height) in such a way as to increasesignificatly the fatigue life.
The results obtained at the University of Pisa for the
stiffener-stiffener connection have been used in the preliminary studies
for the design of the Messina Bridge in Italy (suspended steel bridge, with
a span of 3300 metres and with six lanes for road traffic and two rail
ways).
The results obtained by the testing of the bolted connection ofthe orthotropic deck to cross-beam are used for the design of repairing the
Oosterweelburg in Antwerpen and the design of the new Kruiskansbridge.
8. CONCLUSIONS.
The first two phases of this common reserach programme were
concerned with the collection of traffic data needed to determine loads on
road bridges. This third phase concerned the fatigue behaviour oforthotropic steel decks.
It was necessary to analyse the fatigue behaviour of all the
connections in the orthotropic deck. Because of the scale of the problem,
it was not possible for all the testing and analysis to be carried out in a
reasonnable timescale in one laboratory or one country. A common research
programme was therefore formulated and the work distributed between seven
laboratories situated in six countries of the European Community.
For some connections improvements in the design are suggested :
for others, unexpected behaviour occurred which require further
investigations.
Stiffenei—pkate connection.
A welding procedure has been defined which gives a much better
fatigue resistance and excludes cracks in the weld.
- 112
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 121/132
The calculation method developed allows alternative stiffener
shapes to be assessed which may lead to an improved deck design.
A fracture mechanics model has been developed and calibrated using
the experimental results. Such a model, which can be used on a microcomputer, has already been used successfully to study fatigue problems on
existing bridges.
Stiffener-stiffener connection
The tests on the stiffener-stiffener connection with backing
strips showed the importance od the root gap before welding and indicated a
better behaviour of triangular compared with trapezoidal stiffeners.
Triangular stiffeners butt welded from both sides dit not give the
expected improvement in fatigue strength over the butt weld made from one
side on a backing strip.
This important information can be directly applied by bridge
builders. However, further investigations are required to clarify these
results and assess the influence of construction procedures and residual
stresses.
Fatigue cracks are expected to develop in this connection on
existing bridges in a short time. Repair procedures should therefore be
developed as a matter of urgency.
Stiffener crossbeam connection.
Test results from the stiffener-crossbeam connection indicate a
minimum fatigue classification of Eurocode class 80. However, cracks
occured where they were not expected and more information is required on
the shape of the cut-outs in the crossbeam.
A cut-out around the apex of the triangular rib gave an
improvement in fatigue strength over a welded all round connection.
However, cracks developed unexpectedly at small cut-outs near the deck
plate.
Conversely, for trapezoidal ribs, cout-outs around the apex of the rib
reduced the fatigue strength, the "optimised" shape of cut-out proposed for
Germam railway bridges dit not give the expected improvement in fatigue
strength in these tests.
113
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 122/132
Before new tests are carried out, a computer analysis of the
stress distribution at the critical points is necessary to explain this
behaviour an to assess new shapes of this connection.
Bolted connections.The fatigue tests on bolted connections show that the
classification given in Eurocode 3 corresponds to the worst case.
This connection, which occurs frequently in steel bridges, needs further
investigation in order to define more realistic S-N curves.
Results from tests carried out under variable amplitude loading
generally showed good agreement with lives estimated using the Miner rule.
It may be concluded that in furture, fatigue tests can be carried
out mainly under constant amplitude loading. These tests are more
economical. Only a small number of tests under variable amplitude loading
are then required to confirm the application of the Miner rule for each
particular case.
This work gives a lot of information on orthotropic steel decks
which can be used directly by bridge designers and builders. However, some
problems remain which require furhter investigation.
114
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 123/132
BIBLIOGRAPHY
[1] Dr. Lehrke
"Messung und Interpretation von Dynamischen Lasten an StahlbrUcken".
Forschungsvereinbarung Nr. 7210-KD/119 - Abschlussbericht - Phase 3.
Fraunhofer - Institut rur Betrieksfestigkeit.
[2] A. BRULS - E. POLEUR.
"Mesures et Interprétation des Charges dynamiques dans les Ponts".
Recherche n° 7210-KD/201 - Rapport final - Phase 3.
Service Ponts et Charpentes, Université de Liège.
[3] A. BIGNONNET (IRSID) and CARRACILLI, B. JACOB (L.C.P.C.)
"Mesures et Interprétation des charges dynamiques dans les Ponts".
Recherche n° 7210 - KD/317 - Rapport final - Phase 3.Institut de Recherches de la Sidérurgie Française.Laboratoire Central des Ponts et Chaussées.
[H] S. CARAMELLI, P. CROCE, M. FROLI, L . SANPAOLESI.
"Misure ed Interpretazioni dei Carichi dinamici sui Ponti".Convenzione n°7210 - KD/¿)11 - Relatione technica finale - Fase 3
Instuto di Scienza delle Costruzioni, Università di Pisa.
[5] H. KOLSTEIN, J. de Back.
"Mesurements and Interpretation of dynamic loads in Bridges".Agreement Number : 7210-KD/609 - Final Report - Phase 3.
Delft University of Technology - Stevin Laboratory.
[6] C. BEALES.
"Measurements and Interpreation of dynamic Loads in Bridges".
Agreement Number : 7210 - KD/807 - Final Report - Phase 3.
Transport and Road Research Laboratory.
[7] DE BACK, A. BRULS, J. CARRACILLI, E. HOFFMANN, L. SANPAOLESI, J.P. TILLYand J.M. Zaschel.
"Measurements and Interpretation of dynamic Loads on Bridges".
Synthesis Report - Phase 1.
Commission of the European Communities.
EUR 775^ FR, EN, DE (1982).
[8] E. HAIBACH ,J. De BACK, A. BRULS, J. CARRACILLI, B. JACOB, M.H. KOLSTEIN,
J.PAGE, M.R. PFEIPER, SANPAOLESI, TILLY, ZACHEL, HOFFMAN.
Measurements and Interpretation of dynamic Loads on Bridges".
Synthesis Report - Phase 2.Commission of the European Communities.
EUR 9759 FR, EN, DE (1986).
- 115 -
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 124/132
[9] A. BRULS, B. JACOB, G. SEDLACEK and all.Traffic data of the European countries.Eurocode on action - Part 12 : Traffic loads on Bridges.Report of working groupe 2.
[10] NBN5 "Ponts en acier - projet 1987".
Institut Belge de normalisation, Bruxelles.[11] BS 5400 - Steel, concrete and composite bridges. Part 10 : Code of
practice for fatigue. British Standards Institution, London, 1980.
[12] Eurocode n°3 : Design Steel Structures. Final Draft. December 1988.
[13] NEN 2063. "Arc Welding - Fatigue loaded structures - Calculation ofwelded joints in unelloyed and low-alloy steel up to an including Fe510 (Fe 52)".Nederlands Normalisatie Instituut march 1988. Delft.
[14] MADD0X S.J.
"The fatigue behaviour of tropezoïdal stiffener to deck plate welds inorthotropic bridge decks".T.R.R.L. Supplementary Report 96 U.C.
[15] TH0NNARD - JANSS."Comportement en fatigue des dalles orthotropes avec raidisseurstrapézoïdaux.CRIF : Section Métallique - MT lol - Août 1985.
[16] D.E. NUNN AND J.R. CUNINGHAME.
"Stresses under wheel loading in a steel orthotropic deck with VStiffeners".
TRRL Report 59 U.C.
[17] D.E. NUNN AND J.R. CUNINGHAME.
"Stresses under wheel loading in steel orthotropic deck withtrapézoïdal stiffeners".TRRL Report 53 U.C.
[18] HUber M.H. "Die Grundlagen einer rationellen Berechnung der kreuzweisebewerthn Eisenbetonplatten". Zeitschrift der Osterreiches Ingenieurund Architekten-Vereines, n.30, 1914.
[19] Pelikan W., Esslinger M. : Die Stahlfahrbahn, Berechnung undKonstruction". M.A.N. Forschungsheft, 7, 1957.
[20] CROCE P. : "Linfluenza della variabilità di sezione nelle nervature diuna piastra ortotropa". Atti dell'Istituto di Scienza delleCostruzioni, n.252, vol. XVIII, Pisa, 1988.
[21] LEVY M. : "Sur l'équilibre élastique d'une plaque rectangulaire".Compte rendu acad. S c , 129 1989.
[22] CUNINGHAME J.R.Steel bridge decks : Fatigue performance of joints betweenlongitudinal stiffeners. TRRL. Report. LR 1066.
116
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 125/132
[233 K. YAMADA
Fatigue Strength of Field-Welded Rib Joints of Orthotropic SteelDecks.IIW. Doc. XIII 1282-88.Department of Civil Engineering, Nagoya University.
[24] TROMP : Fatigue of field splices in ribs of orthotropic steel bridgesdecks. Report 6-7*1-15.Stevin Laboratory - Steels structures - Delft University ofTechnology 197*1.
[25] A. BRULS
Mesures et interprétation des charges dynamiques dans les ponts.2ème phase. - REcherche CECA. Rapport EUR. 8864.
[26] E. HAIBACH, PLASIL.
Untersuchen sur Betriebsfestigkeit von Stahlleichtfahrbahnen mit
Trapezhohlsteifen im Eisembahnbrückenbau.Der Stahlbau 53~S 269-27*1. 1983.
117
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 126/132
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 127/132
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 128/132
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 129/132
European Comm unities — Commission
EUR 13378 - Meas ureme nt and interpretation of dynamic loads inbridgesPhase 3: Fatigue behaviour of orthotropic steel decks
A. Bruls
Luxem bourg: Office for Official Publications of the European Com munities
1991 - VI, 117 pp., num . tab., fig. - 21.0 x 29.7 cm
Technical steel research series
ISBN 92-826-0532-9
Catalogue number: CD-NA-13378-EN-C
Price (excluding VAT) in Luxembourg: ECU 10
This research, carried out with the financial help of the European Coal andSteel Community, concerned the fatigue strength of orthotropic steel decksof road bridges. It followed two phases that were con cerned with the collection of traffic data and the me asurement of stresses produce d in bridges. Fatigue tests under constant and variable amplitude were carried out on stif-
fener-plate co nnections, stiffener-stiffener connec tions with U and V shapes,and stiffener cross-beam connec tions. From the test results and calculationssome co nclusions can be drawn which are directly usable in bridge design.However, some unexpected behaviour occurred and some connectionsneed further investigation.
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 130/132il IIIMIIIIIIIIIIKI II
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 131/132
Venta y suscr ipc iones • Salg og abonnement • Verkauf und Abonnemen t • Πωλήσεις και συνδpoμές Sales and subscr ip t ions • Vente et abonnements • Vendita e abbonament i
Verkoop en abonnementen • Venda e assinaturas
BELGIQUE / BELGIË
Mon i t eu r be lge / Belgisch S t a a t s b l a d
Rue de Louva i n 42 / L e u v e n s ew eg 42 1000 Bruxe l l es / 1000 Brusse l Tél. (02) 51 2 00 26 Fax 51 1 01 84 CC P / Pos t r e ken i ng 0 0 0 - 2 0 0 5 5 0 2 - 2 7
Aut res d i s t r i bu t eu r s / Over ige v e r k o o p p u n t e n
Librairie e u r o p é e n n e / Europese Boekhan de l
Avenue A l be r t Jonna r t 50 / Albert Jonna r t l aan 50 1200 Bruxe l l es / 1200 Brusse l Tél. (02) 734 02 81 Fax 735 08 60
Jean De Lan n oy
Avenue d u Ro i 202 / K on i ngs l aan 20 2 1060 Bruxe l l es / 1060 B rus se l Tél . (02) 538 51 69 Télex 6 3 2 2 0 UNBOOK B Fax (02) 538 08 41
CR EDOC
Ru e d e la Mon t a g n e 34 / Bergs t raa t 34 Bt e 11 / Bus 11 1000 Bruxe l l es / 1000 B rus se l
DANMARK
J. H. Schu l t z I n fo rma t i on A /S
EF -Pub l i ka t i one r
Ott i l iavej 18 2500 Valby Tlf. 36 44 22 66 Fax 36 44 01 41 Gi rokon t o 6 00 08 86
BR DEUTSCHLAND Bundesanze ige r Ver l ag
Brei te St raße Pos t fach 10 80 06 5000 Köln 1 Tel. (02 21 ) 2 0 29 -0 Fernschre iber : ANZEIGER BONN 8 882 595 Fax 20 29 27 8
GREECE
G.C . Ele f the roudak i s SA
In te rna t iona l Books t o r e Nikis St ree t 4 10563 A thens Tel. (01) 32 2 63 23 Telex 2 1 9 4 1 0 ELEF
Fax 323 98 21
ESPANA
Boletín Ofic ia l del Es tado
Trafalgar, 27 28010 Mad r i d Tel. (91) 44 82 13 5
Mund i - P r e n s a L ib ros , S.A.
Castel lÓ. 37 28001 Mad r i d Tel. (91) 43 1 33 99 (L ibros)
43 1 32 22 (Susc r ipc iones ) 435 36 37 (D i recc ión)
Télex 4 9 3 7 0 -MP L I - E Fax (91) 575 39 98
Sucu rsa l :
Librería I n t e rnac iona l A E D O S Conse jo de C ien t o . 391 08009 Ba rce l ona Tel. (93) 30 1 86 15 Fax (93) 317 01 41
Ll ibrer ia de la Gene ra l i t ä t de Ca ta lunya
Ramb l a de is Estud is . 1 1 8 (Palau Moja) 08002 Ba rce l ona Tel . (93) 30 2 68 35
30 2 64 62 Fa x 30 2 12 99
FRANCE
Journa l officiel Serv i ce des pub l i ca t i ons des C ommun a u t é s eu r op é e n n e s
26 . ru e Desaix 75727 Paris Cedex 15 Té l . (1) 40 58 75 00 Fa x (1) 40 58 75 74
IRELAND
Gove r nmen t Publ icat ions Sa l es Off ice
Sun A l l i ance Hou s e
Mo l eswo r t h St ree t Dubl in 2 Tel . 71 03 09
or by pos t
Gove r nmen t Sta t i one ry Off ice
EEC Sec t i on
6 th f l oor B i shop St ree t Dubl in 8 Tel . 78 16 66 Fa x 78 06 45
ITALIA
Licosa Spa
Vi a Benede t t o For t i n i , 120 / 10 Case l la pos ta le 552 50125 Fi renze Tel. (055) 64 54 15 Fa x 64 12 57 Te lex 570466 L ICOSA I CCP 34 3 509
Subagen t i :
Librer ia scien t i f ica Lucio de Biasio - AE I OU
Vi a Merav ig l i . 16 20123 Mi lano Te l . (02) 80 76 79
Herde r Edi t r ice e Librer ia
Piazza Mon tec i t o r i o . 117 -120 00186 Roma Tel. (06) 67 9 46 28/679 53 04
Librer ia giur id ica
Vi a XII Ot t ob re . 172/R 16121 Genova Tel . (010) 59 56 93
GRAND -DUCHÉ DE LUXEMBOURG
A bo n n emen t s seu l emen t Subsc r i p t i ons on ly Nu r fü r A bo n n emen t s
Mess age r i e s Pau l Kraus
1 1. ru e Ch r i s t ophe P lan t in 2339 L u x embou r g Tél. 49 9 88 88 Télex 2515 Fa x 499 88 84 44 CCP 49242 -63
NEDERLAND
S DU Ove rhe ids i n fo rma t i e
Externe Fondsen Pos t bus 20014 2500 EA ' s -G ravenhage Tel . (070) 37 89 91 1 Fa x (070) 34 75 77 8
PORTUGAL YUGOSLAV IA
Imprensa Nac iona l
Casa da Moeda , EP Rua D. F ranc i s co Manue l de Me l o . 5 P-1092 L i s boa Code x Tel . (01) 69 34 14
D is t r i bu ido ra de Livros Ber t rand , Ld . a
G rupo Ber t rand , SA
Ru a das Ter ras d o s Vales . 4 -A A pa r t a d o 37 P-2700 Amado r a Codex Tel . (01) 49 59 0 50 Te lex 15798 BERDIS Fa x 49 60 25 5
UN ITED K INGDOM
H M SO Book s (P C 16 )
HMSO Pub l i ca t i ons Cen t r e 51 Nine E lms Lane L o n d o n SW 8 5D R Tel . (071) 87 3 9 0 9 0 Fa x GP3 873 8463 Te lex 29 71 13 8
Sub -agen t :
Alan A rms t r o n g L td
2 A rkw r i gh t Road Read i n g , Berks RG 2 OSO Te l . (0734) 75 18 55 Te lex 849937 AAA LTD G Fa x (0734) 75 51 64
OSTERRE ICH
Man z ' s c h e Ve r l a g s -un d Un ive rs i t ä t sbuchhand lung
Koh lma r k t 16 1014 Wien
Tel . (0222) 531 61 -0 Te lex 1 1 25 00 BOX A Fa x (0222) 531 61 -81
BTJ
Bo x 200 2 2 1 0 0 Lund Tel . (046) 18 00 00 Fa x (046) 18 01 25
SCHWE IZ / SUISSE / SVIZZERA
O S E C
S tamp fenbachs t r aße 85 8035 Zü r i c h
Te l . (01) 36 5 51 51 Fa x (01) 36 5 54 11
MAGYARORSZAG
Agro in fo rm
Közpon t :
Budapes t I.. Att i la út 93 . H-1012
Le v è l c ím :
Budapes t , Pf.: 15 H-1253 Tel . 36 (1) 56 82 11 Te lex (22) 4717 AGINF H-61
POLAND
Bus iness Founda t i on ul . Wspó l n a 1/3 PL -00 -529 Warszawa Tel . 48 (22) 21 99 93/21 84 20 Fa x 48 (22) 28 05 49
Privredn i Vjesn ik
Bulevar Len j ina 171/X IV 11070 - B eo g r a d Te l . 12 3 23 40
TURK IYE
Pres Dag i t im T i ca re t ve sanay i A . Ş .
Na r l i bahçe Sokak No . 15 Caga l og l u I s tanbu l Te l . 512 01 90 Te lex 23822 DSVO-TR
AUTRES PAYS OTHER COUNTR I ES ANDERE LÄNDER
Off ice des pub l i ca t i ons of f ic ie l les de s C ommun a u t é s eu r op é e n n e s
2, ru e Merc ie r L-2985 L u x embou r g Tél. 49 92 81 Télex PUBOF LU 1324 b Fa x 48 85 73 CC banca i r e BI L 8 - 1 0 9 / 6 0 0 3 / 7 0 0
CANADA
Renou f Publ ishing Co . L td
Mai l o rde r s — Head Of f i ce :
1294 A l g oma Road O t t aw a . On ta r i o K 1B 3W 8 Tel . (613) 74 1 43 33 Fa x (61 3) 74 1 54 39 Telex 0534783
Ot t awa Store : 61 Spa r k s St ree t Te l . (613) 23 8 89 85
To ron t o S to re : 21 1 Y on g e St ree t Tel . (416) 363 31 71
UNITED STATES OF AMER ICA
UN I PUB
4611 -F Assemb l y Drive L a n h am , MD 2 0 7 0 6 - 4 3 9 1 Te l . To l l Free (800) 2 74 4888 Fa x (301) 459 0056
AUSTRAL IA
Hun te r Pub l i ca t i ons
58 A G i p p s St ree t Co l l i n gwood V ic to r ia 3066
J APAN
K inokun i ya C omp a n y L td
17-7 Shin juku 3 -C h ome Sh i n j u ku - ku To k y o 160-91 Tel. (03) 3439-0121
Journa l Depa r tmen t
PO Box 55 Ch i t ó se Tokyo 15 6 Tel . (03) 3439 -0124
7/30/2019 Fatigue Behaviour of Orthotropic Steel Decks
http://slidepdf.com/reader/full/fatigue-behaviour-of-orthotropic-steel-decks 132/132
NOTICE TO THE READER
All scientific and technical reports published by the Commission of the European Communities
are announced in the monthly periodical 'euro abstracts'. For subscription (1 year: ECU 92)please write to the address below. oa
o
Top Related