Development of idealized explicit FEM using GPU parallelization and its application to large-scale analysis of residual stress of multi-pass welded pipe joint

Abstract

In this research, the authors developed the idealized explicit finite element method (IEFEM) to achieve shorter computing time and lower memory consumption in analyses of welding deformation and residual stress. IEFEM was parallelized by a graphics processing unit (GPU) to achieve even faster computation. To show its applicability to large-scale problems, the proposed method was applied to the analysis of the multi-pass welding of V-groove pipe joint that has 1 million elements, 13 layers, and 33 passes. In the analysis, isotropic hardening, kinematic hardening, and combined hardening were considered to investigate the influence of hardening rule on residual stress distribution. As a result, it is found that residual stress distributions were larger in the order of isotropic hardening, combined hardening, and kinematic hardening. In addition, the analyzed residual stress and experimental measurements showed good agreement. The computing time was approximately 70 h. From these results, it was shown that IEFEM can analyze a large-scale welding residual stress problem in realistic time with high accuracy.