Weld Design And Specification - University Of Delaware
Weld Design andSpecificationJim Glancey, PEDepts. of Bioresources Engineering& Mechanical EngineeringUniversity of Delawarejglancey@udel.eduhttp://udel.edu/ jglanceyI can’t explain everything . . .1000 ft4 in6 in1/4”Inside weld entire length1
Factors in Weld DesignI Strength (static and/or fatigue)I Material and the effects of heatingI CostI DistortionI Residual StressesI Easy to WeldStatic StrengthI Stress- strain diagramFAStress (σ) FAStrain (ε) Lultimate(tensile)yield LLF2
Shear StrengthI Ingeneral, material fails in shear due todistortion (at a molecular level)I Criteria for failure: Ductile: Shear Strength 0.5 Tensile Strength Brittle: Shear Strength 0.75 Tensile StrengthI Weldstrength analysis is generally based onShear Strength3
Static Strength of WeldsButtFNormal F1/875oFilletShear 3/81/42FFw*hFw*hFFMax Normal 0.618w * hFMax Shear F0.707w * hh throat size!Weld Size vs. Throat SizeButth plate thickness weld size1/875oFillet3/81/4h 0.707 * plate thickness0.707 * weld size4
Fatigue StrengthStatic Tensile Cycle1000InfiniteLife1,000,000Cycles of Loading5
Endurance LimitI For Steel: Endurance Limit 0.5 * Tensile Strengthor 100 kpsi, which ever is lower.I For Aluminum: No endurance limit (cannot have an infinitelife)6
Factors for Fatigue Stress AnalysisType of WeldStress IncreaseButt Weld1.2Transverse Fillet1.5Parallel Fillet2.7T-butt with corners2.07
Strength ConsiderationsI Tryto minimize the stresses in welds; makethe parent materials carry highest stresses.I Butt welds are the most efficientI Avoid stress concentrationsI Intermittent weld length should be at least 4times the fillet sizeI Minimize weld size to reduce potential forfatigue failure8
Effects of Welding on MetallurgyI Depends on the alloy and welding processI In general, cracking is promoted by: stress concentrations brittle parent material after welding (lowcarbon steels) hydrogen in the weld metal impurities in the weld metal9
Reducing DistortionI PreventoverweldingI Intermittent weldingI Minimize number of passesI Place welds near the neutral axis of the partI Balance welds around the neutral axisI Anticipate shrinkage forcesI Residual stress relief10
Neutral AxisI The line (plane) where bending stresses arezero.11
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2 Factors in Weld Design IStrength (static and/or fatigue) IMaterial and the effects of heating ICost IDistortion IResidual Stresses IEasy to Weld Static Strength IStress - strain diagram Strain (ε) Stress (σ)F A L L yield ultimate (tensile) F F A L
The optional chain can be adapted to the WELD CRAWLER (ZGN-SCN-WELD CRAWL ER). The chain can be used on a pipe that is up to 48" in diameter. 10048079 ZGN-SCN-WELD CRAWLER- OPT-AXIAL The axial weld solution option allows axial weld inspection using the WELD CR AWLER base (ZGN-SCN-WELD CRAWL
Weld toe radius is the radius which joining the fillet weld and base metal. Figure 2: Weld toe of cruciform shape fillet weld joint The objectives of this paper are as follows: Analysis and compare the effect of weld toe radius on tensile strength of fillet weld
Part of original welding kit. 6) T20004 Fillet Weld Tip ¼" fillet weld tip used for butt and right angle welds. 7) T20005 Fillet Weld Tips 3/8" fillet weld tip used for butt and right angle welds. 8) T20011 Fillet Weld Tips ½" fillet weld tip used for butt and right angle welds. 9) T20009 Ribbon Weld Tip used for welding thermoplastic
immunity (WFI) resist electromagnetic fields emitted by weld guns up to 100 kA/m. Weld-spatter Electromagnetic Weld Fields PROBLEM Hot welding-spatter (a.k.a. weld debris, weld slag, weld berries) sticks to sensor faces and bodies and causes pre
the quality of the weld bead generated by the welding system [10]. Distance sensors are also used to identify and track the weld seam during inspection [11]. Seam tracking systems have been developed to guide a weld gun along a weld seam to improve weld bead quality. For these systems, online inspection of the weld bead is still needed to
Busbar Weld If we consider the weld to the busbar to be a resistor, measuring the impedance is as simple as connecting a current source to the weld and measuring the voltage as shown in Figure 2. HI Current Source LO HI Voltmeter LO Weld Figure 2: Simple weld resistance circuit. The impedance of the weld is then calculated using Ohm's Law.
Graphic symbol that indicates weld required Welding symbol Following eight elements: Reference line (required) Arrow (required) Basic weld symbols Dimensions and other data . Seam Weld Elementary Weld Symbols . Edge Weld Surfacing Elementary Weld Symbols . SUPPLEMENTARY SY
Size of fillet weld (S) : The sides containing the right angle of the fillet weld are called legs. The size of the weld is specified by the minimum leg length. S – is the size of the weld From, Annex A.2.1.8 of IS 9595 :1996 Thickness of Thicker plate Minimum size of fillet weld ¾Maximum size of weld
