SIMULATION OF NONLINEAR HEAT TRANSFER AND RESIDUAL STRESS FOR MULTI-PASS WELDING

Welding residual plastic strains and stresses of welded structures are complicated and they will cause errors during the assembly of the structure and reduce the strength of the structure. Based on an elastic-plastic-model, a 3D finite element numerical simulation of a representative penetration assembly with loop welding line is carried out in this paper. The method of join for penetration structure and base plate is multi-pass welding. The transient temperature field and the real-time dynamic stresses field of the structure are obtained due to different welding sequences during multi-pass welding. In the process of analysis, the heat source is modeled as a moving heat flux along girth welds following a double ellipsoid distribution and the temperature-dependent properties of materials are considered. Being compared with the analysis results of other's and the theory study, which provide instruction to the numerical simulation of welding process on similar components, the simulated results show mostly conformity.