1

Weld Joints Weld TypesWeld Joints Weld Types

ME 538 – Welding Design, Fabrication & Quality Control 1[Cary: Modern Welding Technology, 1998]

Fillet WeldsFillet Welds

ME 538 – Welding Design, Fabrication & Quality Control 2

2

Groove WeldsGroove Welds

ME 538 – Welding Design, Fabrication & Quality Control 3

Examples of Groove WeldsExamples of Groove Welds

ME 538 – Welding Design, Fabrication & Quality Control 4CWA W59 Appendix E

Edge Weld

3

Butt Joint & Applicable Weld TypesButt Joint & Applicable Weld Types

ME 538 – Welding Design, Fabrication & Quality Control 5

[AWS Handbook, 9th ed., Vol.1, Chap.5, and CSA W59-M1989 Standard]

Corner Joint & Applicable Weld TypesCorner Joint & Applicable Weld Types

ME 538 – Welding Design, Fabrication & Quality Control 6

[AWS Handbook, 9th ed., Vol.1, Chap.5, and CSA W59-M1989 Standard]

4

T T –– Joint & Applicable Weld TypesJoint & Applicable Weld Types

ME 538 – Welding Design, Fabrication & Quality Control 7

[AWS Handbook, 9th ed., Vol.1, Chap.5, and CSA W59-M1989 Standard]

Lap Joint & Applicable Weld TypesLap Joint & Applicable Weld Types

ME 538 – Welding Design, Fabrication & Quality Control 8

[AWS Handbook, 9th ed., Vol.1, Chap.5, and CSA W59-M1989 Standard]

5

Edge Joint & Applicable Weld TypesEdge Joint & Applicable Weld Types

ME 538 – Welding Design, Fabrication & Quality Control 9

[AWS Handbook, 9th ed., Vol.1, Chap.5, and CSA W59-M1989 Standard]

Standard Locations of Elements of a Welding SymbolStandard Locations of Elements of a Welding Symbol

ME 538 – Welding Design, Fabrication & Quality Control 10[AWS Handbook, Vol. 1, also ANSI/AWS Standard A2.4-98]

6

The Weld Joint & Reference LineThe Weld Joint & Reference Line

ME 538 – Welding Design, Fabrication & Quality Control 11[Cary: Modern Welding Technology, 1998]

Groove Weld SymbolsGroove Weld Symbols

ME 538 – Welding Design, Fabrication & Quality Control 12[AWS Handbook, Vol. 1, also ANSI/AWS Standard A2.4-98]

7

Fillet and Other Weld SymbolsFillet and Other Weld Symbols

ME 538 – Welding Design, Fabrication & Quality Control 13[AWS Handbook, Vol. 1, also ANSI/AWS Standard A2.4-98]

Supplementary SymbolsSupplementary Symbols

ME 538 – Welding Design, Fabrication & Quality Control 14[AWS Handbook, Vol. 1, also ANSI/AWS Standard A2.4-98]

Finishing Codes

8

Welding, Brazing & Soldering Welding, Brazing & Soldering Process DesignationsProcess Designations

ME 538 – Welding Design, Fabrication & Quality Control 15[AWS Handbook, Vol. 1, Chap. 8]

Example: Welding Symbols with Example: Welding Symbols with Multiple Reference LinesMultiple Reference Lines

ME 538 – Welding Design, Fabrication & Quality Control 16[AWS Handbook, Vol. 1, Chap. 8]

9

Example: Welding Symbols forExample: Welding Symbols forIntermittent Fillet WeldsIntermittent Fillet Welds

1/4

1/4

1/4

1/4

ME 538 – Welding Design, Fabrication & Quality Control 17[AWS Handbook, Vol. 1, Chap. 8]

All units are Inches

Example: Brazing & Soldering SymbolsExample: Brazing & Soldering Symbols

FS

ME 538 – Welding Design, Fabrication & Quality Control 18[AWS Handbook, Vol. 1, Chap. 8]

FS

10

Selection of the Joint TypeSelection of the Joint Type

The most appropriate joint type for an application will depend on:

1. The required part geometry2. The ability of the joint to transfer the load3. The welding position4. Accessibility of the joint for welding and

inspection

ME 538 – Welding Design, Fabrication & Quality Control 19

inspection 5. Joint preparation and welding costs6. Governing code and qualification

requirements (Fabrication)

Selection of Weld TypesSelection of Weld TypesSelection of the most appropriate weld type for a joint is based on the ability of the weld to safely transfer the load in service and onto safely transfer the load in service and on the cost of making the weld. The designer can choose:

1. Plug or slot welds

2. Fillet welds for joints subject to lower stress

ME 538 – Welding Design, Fabrication & Quality Control 20

j jor less demanding service conditions

3. Full penetration groove welds for joints in critical service conditions, e.g., high stress or cyclic loading

11

Prohibited Applications of OneProhibited Applications of One--sided Fillet Weldssided Fillet Welds

F

ME 538 – Welding Design, Fabrication & Quality Control 21[AWS Handbook, Vol. 1, Chap. 8]

Example: CSA W59 Required Fillet Lap Joints in TensionExample: CSA W59 Required Fillet Lap Joints in Tension

F

F

ME 538 – Welding Design, Fabrication & Quality Control 22

12

Welding PositionsWelding Positions

Easier,Faster,Higher

DepositionRates,L

Harder,Slower,Lower

DepositionRates,

ME 538 – Welding Design, Fabrication & Quality Control 23[Cary: Modern Welding Technology, 1998]

LessCost

MoreCost

Groove & Fillet Welds PositionsGroove & Fillet Welds Positions

ME 538 – Welding Design, Fabrication & Quality Control 24[CSA W59-M1989 Standard]

13

Pipe Welding PositionsPipe Welding Positions

ME 538 – Welding Design, Fabrication & Quality Control 25[Cary: Modern Welding Technology, 1998]

Examples of Poor Weld AccessibilityExamples of Poor Weld Accessibility

POOR

POOR

POOR

BETTER

BETTER

POOR

POOR

ME 538 – Welding Design, Fabrication & Quality Control 26[J. Hicks, A Guide to Designing Welds, 1989]

BETTER

POOR

14

More Examples of Weld AccessibilityMore Examples of Weld Accessibility

ME 538 – Welding Design, Fabrication & Quality Control 27[J. Hicks, A Guide to Designing Welds, 1989]

Economics of Groove WeldsEconomics of Groove Welds• Square groove welds: Lowest Cost

but thickness is limited– From one side 1/4” to 3/8” (6 to 10

mm) max.– From both sides 1/4” to 1/2” (6 to 12From both sides 1/4 to 1/2 (6 to 12

mm) max.

• Single V or single bevel welds:– Thickness is equal or less than 3/4”

(18 mm)

• Double V or double bevel welds: – Up to 40 mm gives lowest distortion

ME 538 – Welding Design, Fabrication & Quality Control 28

• Single and double J groove welds:– Less weld metal is required, but

requires machining operation

• Single and double U groove welds:– Less weld metal is required, but

requires machining operationWelding & Metal Fabrication, Mar. 1977, pp. 85-91

15

Rule of Thumb for Fillet WeldsRule of Thumb for Fillet Welds

Weld strength is proportional to the weld throat area

Throat Area = 0.707 S x L

To double the strength:

1) Double the size, S, but the volume of weld metal required increases in proportion to S2, i.e., the volume of weld metal required increases by 4 times!

2) Double the length and the volume only doubles

Weld Throat

ME 538 – Welding Design, Fabrication & Quality Control 29

2) Double the length and the volume only doubles

Rule of Thumb for Fillet Welds:Always make a fillet weld small and long

Note: there are usually minimum allowed fillet weld sizes in codes due to metallurgical limitations

[Cary: Modern Welding Technology, 1998]

Volume of Weld Metal for TVolume of Weld Metal for T--JointsJoints

ME 538 – Welding Design, Fabrication & Quality Control 30[AWS Welding Handbook, Vol. 1 (9th Ed.)]

16

Equal Throat/Strength TEqual Throat/Strength T--Joint WeldsJoint Welds

ME 538 – Welding Design, Fabrication & Quality Control 31[AWS Welding Handbook, Vol. 1 (9th Ed.)]

Typical Corner Joint DesignsTypical Corner Joint Designs

ME 538 – Welding Design, Fabrication & Quality Control 32

17

Deposition RatesDeposition Rates

ME 538 – Welding Design, Fabrication & Quality Control 33[AWS Welding Handbook, Vol. 1 (9th Ed.)]

Deposition RatesDeposition Rates

ME 538 – Welding Design, Fabrication & Quality Control 34[AWS Welding Handbook, Vol. 1 (9th Ed.)]

18

Operator FactorOperator Factor

ME 538 – Welding Design, Fabrication & Quality Control 35[AWS Welding Handbook, Vol. 1 (9th Ed.)]

Some General Weld Joint Design GuidelinesSome General Weld Joint Design Guidelines

1. Designed weld strength must be greater than or equal to the required joint strength

2. Use standardized joints whenever possiblej p3. Use complete penetration welds for joints in

tension or fatigue (CP)4. Always choose a joint preparation that minimizes

machining costs and the amount of weld metal and welding time required

5. Always use the smallest fillet or partial penetration ld i ll d

ME 538 – Welding Design, Fabrication & Quality Control 36

weld size allowed6. Use intermittent fillet welds whenever possible, but

be aware of minimum length & pitch requirements

7. Always try to reduce the number of welds required

8. Avoid overwelding[Cary & Helzer: Modern Welding Technology, 2005]

19

Some General Weld Joint Design GuidelinesSome General Weld Joint Design Guidelines

9. Remove material in butt joints between different thicknesses for better transition (don’t add material)

10.Try to avoid using double T or cruciform joints

11.Always bevel the thinner member of corner joints

12.Avoid plug or slot welds in highly stressed members

13.Use flat welding position whenever possible

14 Welding in an enclosed area must be well ventilated

ME 538 – Welding Design, Fabrication & Quality Control 37

14.Welding in an enclosed area must be well ventilated

15.Always ensure accessibility

16.Weld symbols must be clear and unambiguous

[Cary & Helzer: Modern Welding Technology, 2005]

Practical Welding Design PrinciplesPractical Welding Design Principles

1. Secondary Member: There is no secondary member in a welded structuremember in a welded structure

2. Transverse Forces: Always provide a path so that a transverse load can enter part/parts of the weldment that lie parallel to the load

3. Force Redirection: Always provide a component when a force changes direction

ME 538 – Welding Design, Fabrication & Quality Control 38

p g4. Weld Details vs. Welder’s skill: Always avoid a

joint design where the skills of the welder determine the weld’s integrity

[Cary & Helzer: Modern Welding Technology, 2005]

20

Examples: CSA W59 Minimum Allowed Weld Examples: CSA W59 Minimum Allowed Weld Sizes for Welded Steel ConstructionSizes for Welded Steel Construction

ME 538 – Welding Design, Fabrication & Quality Control 39[CSA W59-M1989 Welded Steel Construction]

Examples: Secondary MembersExamples: Secondary Members

ME 538 – Welding Design, Fabrication & Quality Control 40

21

Examples: Transverse ForcesExamples: Transverse Forces

A force applied transverse to a member will ultimately enter a portion of the section that lies parallel to the p papplied force

ME 538 – Welding Design, Fabrication & Quality Control 41[AWS Welding Handbook, Vol. 1 (9th Ed.)]

Provision for Transverse ForceProvision for Transverse Force

ME 538 – Welding Design, Fabrication & Quality Control 42

Poor DesignBetter Design

[AWS Welding Handbook, Vol. 1 (9th Ed.)]

22

Example: Attachments with Transverse LoadsExample: Attachments with Transverse Loads

ME 538 – Welding Design, Fabrication & Quality Control 43[AWS Welding Handbook, Vol. 1 (9th Ed.)]

Example: Attachments with Transverse LoadsExample: Attachments with Transverse Loads

ME 538 – Welding Design, Fabrication & Quality Control 44[AWS Welding Handbook, Vol. 1 (9th Ed.)]

23

Example: Attachments with Transverse LoadsExample: Attachments with Transverse Loads

ME 538 – Welding Design, Fabrication & Quality Control 45[AWS Welding Handbook, Vol. 1 (9th Ed.)]

Example: Designing for Transverse ForcesExample: Designing for Transverse Forces

PoorDesign

ME 538 – Welding Design, Fabrication & Quality Control 46[Blodgett, Eng. J. - AISC, 1980, 17(4), pp. 106-119]

Better:Add

External GussetPlates

Best:Add

InternalStiffenerPlates

24

Force RedirectionForce Redirection

ME 538 – Welding Design, Fabrication & Quality Control 47

Weld Details vs. Welder’s Skill Weld Details vs. Welder’s Skill

ME 538 – Welding Design, Fabrication & Quality Control 48

Poor Design Better DesignO.W. Blodgett, Eng. J.-AISC, 17(4),1980,106-119

25

Weld Details vs. Welder’s Skill Weld Details vs. Welder’s Skill

A weld mustA weld muststart and stop sono crater is leftat points of highstress

(AWS Standard D1.1and CSA W59 Welded

ME 538 – Welding Design, Fabrication & Quality Control 49O.W. Blodgett, Eng. J.-AISC, 17(4),1980,106-119

and CSA W59 WeldedSteel Construction)