Opportunities of advanced viscoplastic material modelling for the numerical prediction of thermal and residual stresses in high-strength low-alloy steel welds

摘要

The accurate numerical prediction of thermal stresses, residual stresses, and distortions in high-strength low-alloy steel welds is challenging due to the steels' complex hardening, viscoplastic, and phase transformation behaviour. This work demonstrates the opportunities of applying an advanced viscoplastic material model for the numerical simulation of a single-pass gas-metal arc (GMA) weld using steel of grade S960QL. A very good agreement was found between numerically predicted and experimentally measured residual stresses. The opportunities of advanced viscoplastic material modelling in computational welding mechanics (CWM) are further demonstrated by comparing the simulation results with those obtained by applying a classic rate-independent isotropic hardening approach. The numerical simulations did show that simple isotropic hardening formulations result in inaccurate predictions of residual stresses for non-austenitized base material within the heat affected zone (HAZ).