Prediction of Residual Stresses and Distortion in GTAW Process -A Review

Residual stresses and thermal distortion are a common phenomenon observed in any welding method. This is a result of non-uniform stresses generated due to highly localized heating at the joint edges, which fuses the base material and leads to considerable amount of changes in mechanical properties. Thus, it is very important to evaluate these effects in any welded structural members before designing for actual loading condition. Therefore, accurate prediction of these residual stresses and distortion is of critical importance to ensure the in-service structural integrity of welded structures. The recent advancement in Computational simulation and numerical techniques helps in evaluating the weld distortion and residual stresses. The moving heat flux approach and Element birth/death method makes it easier to analyze the weld distortion. This is done with the use of ANSYS Commercial FE software. It has been observed from many researchers, the Residual stresses and distortion were predicted using different simulation methods. The minimum longitudinal residual stress and distortion occurred in the specimen containing ushaped grooves using 2-D and 3-D finite element analysis. The residual stress and the welding distortion in low carbon steel do not seem to be influenced by the solid state phase transformation, because of a small dilation due to martensite transformation. Peak tensile residual stress and angular distortion values were lower in the A-TIG weld joint compared to that of the multi-pass TIG weld joint. This paper focus on overview of Computational simulation and numerical techniques for Prediction of Weld Distortion and Residual Stresses in GTAW Process.