Investigation of external restraining force effects on welding residual stresses using three-dimensional thermal elastic-plastic multi-body coupling finite element model

摘要

A three-dimensional multi-body coupling thermal elastic-plastic finite element (FE) model - in which clamp, clamping strip, worktable, and welding plate are included - is developed to simulate the external restraining force effects on welding residual stresses. Welding experiments are also carried out to measure the restraining forces and transient distortions to validate the model. Simulated results from the multi-body model and the displacement constraints model are compared, the effect of restraints release on welding residual stresses is also analysed. The analysis results show that the simulated transverse residual stresses with the displacement constraints model are larger than those of the multi-body coupling model; the transverse welding residual stress at the welding centre-line clearly varies with increasing restraining force: it decreases on the top surface and increases on the bottom surface after restraints release as the restraining force is small, arid will not be released after restraints release provided that a large restraining force is located close to the weld line.