Fast Simulation for Multi-Pass Welding Process Using Iterative Substructure Method: Investigation of Optimization and Efficient Computation

Residual stress caused by welding processes affects characteristics of strength and fracture of equipment and piping in power plants. Numerical thermal elastic-plastic analysis is a powerful tool to evaluate weld residual stress in actual plants. However, the conventional three-dimensional precise analysis for a welding process such as multi-pass welding, machining and thermal treatment requires enormous computation time though it can provide accurate results. In this paper, the finite element analysis code based on the iterative substructure method that was developed to carry out thermal elastic-plastic analysis efficiently, with both high computational speed and accuracy, was proposed to simulate the welding process of plant equipment and piping. Furthermore, optimization of the proposed analysis code was examined and the computational efficiency and accuracy were also evaluated.