Coupling Computation between Weld Mechanics and Arc Plasma Process for Residual Stress Analysis

Abstract

Abstract This article presents an advanced computational framework to accurately simulate weld residual stress, which is generated as a result of thermomechanical behavior during welding. The basis of the framework is coupled process–mechanics modeling and analysis of gas tungsten arc welding (GTAW). In the developed modeling and analysis, a heat source model dependent on the welding heat input condition was constructed by considering the physics of the welding arc. Formation of the weld pool and temperature field was calculated through a combined conductive and convective heat transfer analysis with the constructed heat source model. Transient temperature fields obtained were used for large-deformation thermal elastic–plastic analysis of residual stress induced by welding. The modeling and analysis were applied to calculate the welding thermomechanical problems of low-carbon austenitic stainless steel. The calculated weld penetration, temperature profiles, and distribution of residual stress in the welds were compared with the experimental measurements to validate the accuracy of the modeling and analysis. The effect of convective heat transfer on weld pool formation was further investigated in relation to a parameter derived from welding thermal conduction theory for a moving point heat source. The dimensions of weld penetration and the convective heat transfer effect were estimated by the parameter. Thus, it was concluded that the developed modeling and analysis techniques successfully achieved an accurate weld residual stress analysis and provided a more detailed understanding of the convective heat transfer effect on weld pool formation.