Finite element analysis of residual stress in hybrid laser-arc welding for butt joint of 12?mm-thick steel plate

摘要

Abstract As a high-efficiency and high-quality welding process, hybrid laser-arc welding (HLAW) has significant potential of application in welding thick plate. Understanding the features of welding residual stress benefits the optimization of HLAW process. In the present study, based on thermal elastic–plastic theory, a three-dimensional finite element model is developed to predict the residual stress and distortion in HLAW for butt joint of 12-mm-thick steel plate. GMAW heat input and laser energy are modeled as one double-ellipsoid body heat source and one cone body heat source with enhanced peak density along the central axis, respectively. Residual stresses and distortions are calculated for single-pass and multi-pass hybrid welding processes. The results show that the distribution features of longitudinal and von Mises equivalent residual stresses in single-pass hybrid welding are similar to that in multi-pass hybrid welding. A large tensile stress is generated at the weld zone and its vicinity. Compared with GMAW, the zone with high residual stress in hybrid welding is decreased largely, but there is no improvement in peak residual stress. Among three cases, the distortion in single-pass hybrid welding has the lowest value.