Design of Welded Connections - Lincoln Electric

8/11/2019 Design of Welded Connections - Lincoln Electric

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DETAILS OF WELDEDCONNECTIONS


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Details of Joints


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Butt

Corner


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Corner Edge


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Tee T

ap


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AWS A3.0 Standard Welding Terms and DefinitionsAWS A3.0 Standard Welding Terms and Definitions

butt oint.A oint between two members ali ned

approximately in the same plane.

corner joint. A joint between two members located

approximately at right angles to each other in the

form of an L.

L


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,


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2.5 : 1 Taper

Radius

>24(600mm)

For steel with Fy > 80 ksi [620 MPa], D14.4 requires a

radius. Fy > 80 ksi [620 MPa], D14.4


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Butt Jointdifferent thicknesses


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AWS D14.4/D14.4M:2005 5.15.1AWS D14.4/D14.4M:2005 5.15.1

Specification for Welded Joints in Machinery and EquipmentSpecification for Welded Joints in Machinery and Equipment

Butt Jointdifferent thicknesses.

1.0


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Slope plate

Slope both


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Slope plate

Slope both


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Secondary Stresses

No Secondary Stresses


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AWS D14.4/D14.4M:2005 5.15.2AWS D14.4/D14.4M:2005 5.15.2


Butt Jointdifferent thicknesses

.

1.0

Required when the offset is greater than the

thickness of the thinner part.


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Butt Joints:

different thickness and width


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Butt Joints:

different thickness and width


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Corner Joint


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Equipment?

Personnel?

Confined Space?


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CORNER JOINTS


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CORNER JOINTS

Lamellar Tearin


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CORNER JOINTS

stresses by using PJP

groove weld if design

.


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CORNER JOINTS

member where lamellar

tearing is suspected.


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TEE JOINT?T

Resists tearing better

concentrated on the

edge.


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TEE JOINT?T

Resists tearing better

concentrated on the

edge.


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Lap Joints


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AWS D14.4/D14.4M:2005AWS D14.4/D14.4M:2005


5.5 Lap Joints

5.5.1 The minimum overlap of parts in stress-carrying lap joints shall be five times the thickness of

the thinner part. Unless lateral deflection of the parts

is prevented, they shall be connected by at least twotransverse lines of fillets, plug or slot welds or by two

or more longitudinal fillet or slot welds.

5.5.1

5


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Lap Joints

.not < 1 (25mm)


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ec an ca uppor

AWS D14 4/D14 4M:2005AWS D14 4/D14 4M:2005


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AWS D14.4/D14.4M:2005AWS D14.4/D14.4M:2005


5.5 Lap Joints

5.5.2 If longitudinal fillet welds are used alone in lap,

weld shall be no less than the perpendicular distance

.

shall not exceed 16 times the thickness of the

connected thinner art unless.

5.5.2

16


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LL >> DD

D


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Groove Weld Types

Sin le Bevel


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Groove Weld Types

Sin le Vee

V


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Groove Weld Types

Sin le U

U


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Groove Weld Types

Sin le J

J


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Sin le Vee versus Sin le U

V vs. U


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Sin le Vee versus Sin le UV vs U


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Groove Weld Types: Single vs. Double

Sin le VeeVvs

Double VeeV


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Groove Weld Types: Single vs. Double

Sin le VeeVvs

Double Bevel K


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D bl V G


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Double Vee Groove

Same depth

V

Unequal depth

G W ld T d


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Groove Weld T pe and

Single Vee in Butt Joint


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Single Vee in Butt Joint

Single Vee in Corner JointV

Single Vee in Tee Joint


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Single Vee in Tee Joint

Single Bevel in Tee JointT

Single Sided Groove Welds


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Single Sided Groove Welds

O en Root

With Backing

Backing


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Backing

TeeCorner

T


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Weld Backing Types:

Steel

Copper

Ceramic


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ar o e men

Notch Effects


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Backing removed,

root backgouged


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Fill cavity, apply


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ec r ca y on uc ve

Metallurgical Effects


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-


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-


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-


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ec r ca y on-con uc ve


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-


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-


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AWS D1.1:2010 Structural Welding CodeAWS D1.1:2010 Structural Welding CodeSteelSteel


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CJP Groove Weld Types:

Prequalified versus Qualified by Test

VS.

AWS D1.1 Prequalified JointsAWS D1.1 Prequalified Joints


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One sided, with steel backing

ee

AWS D1.1 Prequalified JointAWS D1.1 Prequalified Joint


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Two sided, with backgouging


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Air-Arc Gouging

AWS D1.1 Prequalified JointAWS D1.1 Prequalified Joint


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Two sided, with backgouging

AWS D1.1 Qualified by TestAWS D1.1 Qualified by Test


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One sided, open root



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Proper root conditions (rootProper root conditions (root

opening, included angleopening, included angle

(



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Excessive rootExcessive rooto enin leads to melto enin leads to melt--

throughthrough



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Tight root opening leads toTight root opening leads to

incomplete fusionincomplete fusion



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Two sided, without backgouging



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Details of PJP Groove Welds


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PJP Groove Weld: unfused root


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Unacce table: strainin about root


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Acce table: no strainin about root


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Acce table: no strainin about root


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roa < p a e c ness


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PJP Groove Welds

Throat < plate thickness


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Throat < plate thickness

1/4 [6 mm]6mm


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1/16 in [2 mm]


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t

1/16 in [2 mm]

1/16 i


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1/16 in

[2 mm]

ax mum e e

Size Does NotApplyIf t= t,

en

= .


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and > t-1/16

AWS D1.1 Structural Welding CodeAWS D1.1 Structural Welding Code----SteelSteel

2.3.2.3 Minimum Length

The minimum length of a fillet weld shall


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The minimum length of a fillet weld shall

,

the effective size of the weld shall be

considered not to exceed 25% of its

2.3.2.3

25%

= mm ,

then Lmin = 1 (24 mm)


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Leg Size ()

ORif = 1/2 (12 mm)

and L= 1.5 (40 mm),

then min = 3/8 (10 mm)


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Length (L)

eff

Leg Size (

)

AWS D14.4/D14.4M:2005AWS D14.4/D14.4M:2005


5.21 Details of Fillet Welds

5 21 1 6 The minimum length of an


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5.21.1.6 The minimum length of an

intermittent fillet weld shall be 1 in.[40 mm], and spacing shall not

exceed 12 times the thickness of

thinner part, but not more than 6 in.150 mm .

5.21 . . .

12150

Lmin = 1.5 [38 mm] and Lmin = 4


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Leg Size ()

Length (L)

-

T


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< 90o > 90o


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Greater angle


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Greater


2.3.4 Weld Size and Length.

. .

For fillet welds and skewed T-joints, the following shall be


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For fillet welds and skewed T joints, the following shall be

provided on the contract documents.(1) For fillet welds between parts with surfaces meeting at an

angle between 80 and 100, contract documents shall

.

(2) For welds between parts with the surfaces meeting at an

angle less than 80 or greater than 100, the contract

documents shall specify the effective throat.

T

2 80100


pec y e we eg s zewithin these limits:

80o


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80o

80o< 100o

> o< 100o

AWS D1.1:2010 Structural Welding CodeAWS D1.1:2010 Structural Welding Code----SteelSteel

2.3.4 Weld Size and Length.

or e we s an s ewe - o n s, e o ow ng s a e

provided on the contract documents


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provided on the contract documents.

1 For fillet welds between arts with surfaces meetin at an

angle between 80 and 100, contract documents shall

specify the fillet weld leg size.

(2) For welds between parts with the surfaces meeting at anangle less than 80 or greater than 100, the contract

documents shall s ecif the effective throat.

T

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pec y e ec ve roa -effwithin these limits:

for >100o and < 80o


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for >100o and < 80o

>100o

>100o

< < o

t-eff

t-eff

t-eff

t-eff


2.3.5.2 Fillet Welds and Welds in Skewed T-Joints.

The following shall be provided on the shop drawings:

angle between 80 and 100, shop drawings shall show the


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g , p g

fillet weld leg size,(2) For welds between parts with surfaces meeting at an angle

less than 80 or greater than 100, the shop drawings shall

s ow e e a e arrangemen o we s an requ re eg s ze

to account for effects of joint geometry and, where appropriate,

the Z-loss reduction for the process to be used and the angle,

2.3.5.2 T

180 100

Z


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2.4.3.2 Welds in Acute Angles Between 80 and 60 and

in Obtuse Angles Greater than 100.

When welds are deposited in angles between 80 and 60 or


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p g

in angles greater than 100 the contract documents shallspecify the required effective throat. The shop drawings shall

clearly show the placement of welds and the required leg

mens ons o sa s y e requ re e ec ve roa see nnex

B).

. . .

8060 100

B

80o- 100o


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Multiplier

60o 0.71

Multiplier

95o 1.03

5o .7

70o 0 81

.

105o 1 12


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70o 0.81 105 1.12

75o 0.86

80o 0.91

.

115o 1.19

85o

0.9690o 1.0

.

125o 1.25

.

135o

1.31

Adapted from Annex B Table B.1Adapted from Annex B Table B.1


2.4.3.3 Welds in Angles Between 60 and 30.

When welding is required in an acute angle that is less than

u equa o or grea er an gure . , e

effective throat shall be increased by the Z-loss allowance


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Table 2.2 . The contract documents shall s ecif the re uired

effective throat. The shop drawings shall show the required leg

dimensions to satisfy the required effective throat, increased by

e - oss a owance a e . see nnex or ca cu a on o

effective throat).

. . .

60 30 [3.11(D)]

Z2.2

Z

B



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t


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Z-loss

Z

Fillet Weld Terminations


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.

AWS D1.1:2010, clause 2.9.3


. .

2.9.3


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. . . .

sides of parts or may be stopped short or may have

end returns exce t as limited b the followin cases:


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. .

2.9.3


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. . . .

sides of parts or may be stopped short or may have

end returns exce t as limited b the followin cases:


. . . .

2.9.3.2


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edge or side of a part subject to calculated tensile

size of the weld from the start of the extension (see

Fi ure 2.6 .

2.6

Holdback


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2.9.3.3 Maximum End Return Length.

Welded joints shall be arranged to allow the flexibility

2.9.3.3


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assume n e connec on es gn. e ou s an ng

legs of connection base metal are attached with end

,

exceed four times the nominal size of the weld (see

. .

42.7


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2.9.3.4 Transverse Stiffener Welds.

Except where the ends of stiffeners are welded to the

flange, fillet welds joining transverse stiffeners to girder


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webs shall start or terminate not less than four timesnor more than six times the thickness of the web from

the web toe of the web-to-flange welds.

46

AISC makes this applicable when tw < (18 mmm).

Exception to general practice

w


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4t < d < 6t

Cracking can occur in shipping


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Does not apply when stiffeners are welded to flanges


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. . . .

2.9.3.5


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plane shall be interrupted at the corner common to

.


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. . .

drawings shall specify the effective weld length.

2 3 4


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2.3.4

End returns and hold-backs for fillet welds, if

documents.

AWS D14.4/D14.4M:2005AWS D14.4/D14.4M:2005


5.10.1 Fillet welds which support a tensile force that is


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corners of parts or members, but shall be returned

continuously, full size, around the corner for a length

equa o w ce e we s ze w ere suc re urn can e

made in the same plane. Boxing shall be indicated on

design and detail drawings.

5.10.1


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Fillet vs. PJP Groove Weldvs.

Both used in corner, tee joints

s more e c en n use o


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weld metal

T

PJP


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Fillet versus PJP Groove Welds

vs.

Same throat


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50% less metal50% less metal

50%50%

Fillet versus PJP Groove Weldsvs.

Cost to bevel


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Fillet vs. PJP Groove Weldvs.

Both used in corner, tee joints



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s more e c en n use oweld metal

Fillets dont require joint prep.

T

PJP

vs.


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,use fillets

tw 3/4 (20mm)


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If t

> 3/4 (20mm),

tw>20PJP


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AWS A3.0 Standard Welding Terms and DefinitionsAWS A3.0 Standard Welding Terms and Definitions

tack weld.A weld made to hold parts


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the final welds are made.

change stress distribution.


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Tack welds can a ect atigue

erformance


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If cyclically loaded, tack welds to

.

E


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If cyclically loaded, continuous

.

B


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5.18 Tack Welds and Construction Aid Welds

5.18.1 General Requirements

(1) Tack welds and construction aid welds shall be

made with a qualified or prequalified WPS and by qualified

personne .

(2) Tack welds that are not incorporated in final


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( ) p

welds, and construction aid welds that are not removed, shall

meet visual inspection requirements before a member isaccepted.

5.18

5.18.1

(1) WPS(2)


5.18.2 Exclusions. Tack welds and construction aid

welds are ermitted exce t that:

(1) In tension zones of cyclically loaded structures,

there shall be no tack welds not incorporated into the

final weld except as permitted by 2.16.2, nor


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construction aid welds. Locations more than 1/6 of

the depth of the web from tension flanges of beamsor girders are considered outside the tension zone.

5.18.2

(1) 2.16.2

1/6


steel with specified yield strength greater than 70 ksi

,construction aid welds shall require the approval of


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(2)

485MPa


. . . . . ,

welds and construction aid welds, not incorporated

,the Engineer.


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. . . .

Weld Metal Strength

Matching

Undermatching


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Overmatching

Only require for CJP in tension

OK for all welds

Usually used for groove welds

Compares minimum specified values


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Compares minimum specified values

y u ra os = eren

Fy/Fu

UNDERMATCHING STRENGTH

Typical application is fillets,

More crack resistant


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More crack resistant

PJP


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Strength


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Never required in D14.4, AISC

.


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design, may be non-conservative

0.4 Fy t > 0.3 EXX t

y u = .75,

then

u >

e.g., Dont Overmatch0.3 EXX t


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0.4 Fy t

AWS D14.4

Table 2


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AWS D14.4/D14.4M:2005AWS D14.4/D14.4M:2005Specification for Welded Joints in Machinery and EquipmentSpecification for Welded Joints in Machinery and Equipment

CJP Groove Welds


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CJP Groove Weld in Tension


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CJP Groove Welds


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CJP Groove Welds


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CJP Groove Weld in

Compression


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CJP Groove Welds


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CJP Groove Welds


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CJP Groove Welds


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CJP Groove Welds


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PJP Groove Welds


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Plu and Slot Welds


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CJPs in tension

CPJ


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CONNECTIONS


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Design of Welded Connections - Lincoln Electric

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