Fatigue Assessment and LEFM Analysis of Cruciform Joints Fabricated with Different Welding Processes, XIII-2175-07
2007 (English)In: IIW International Institute of Welding: 60th Annual Assembly, 2007Conference paper (Other academic)
In this study fatigue testing and defect assessment were carried out on specimens welded with robotic and manualwelding using fl ux cored (FCAW) and metal cored (MCAW) fi ller materials in order to study the effect of the weldingmethod on the fatigue strength and weld quality. Thirteen different batches were investigated of which two wasshot peened before fatigue testing. The local weld geometry was measured for all the specimens before testing.The specimens welded with fl ux cored weld wire showed the best fatigue strength, small defects and low residualstresses. Large scatter in the fatigue data is observed, especially when manual welding is employed. The few largestdefects were removed by the shot peening process, although small defects survived. This led to a smaller scatterin fatigue live for the shot peened specimens. Linear elastic fracture mechanics, LEFM, was employed for analysisof the fatigue test results. The fatigue life predictions using a 2D LEFM FE-model for simulating a continuous coldlap defect along the weld toe showed a qualitative agreement with the fatigue test results. The 2D analysis showedthat a continuous cold lap defect should be no more than 0.5 mm deep in order to comply with the requirement offatigue lives for normal weld quality according to the IIW design rules. For larger defects (> 0.8 mm) an increased toeradius will have a small effect on the fatigue strength. A 3D LEFM analysis of crack growth from a spatter-inducedcold lap defect was also carried out. This showed similar trends in crack growth compared to the 2D analysis ofa continuous cold lap, although the spatter-induced cold lap defect (semi-elliptical) had a longer fatigue life (x2.7),and hence is less dangerous from a fatigue point of view.
Place, publisher, year, edition, pages
Arc welding; Defects; Fatigue tests; Fracture mechanics; Mechanical tests; Reference lists; Residual stresses; Stress distribution
IdentifiersURN: urn:nbn:se:kth:diva-61597OAI: oai:DiVA.org:kth-61597DiVA: diva2:479406
The 60th Annual Assembly of the International Institute of Welding (IIW). Dubrovnik and Cavtat, Croatia. 1-8 July 2007
QC 201205242012-01-172012-01-172012-05-24Bibliographically approved