Numerical analysis of multi-pass welding residual stresses based on processes chain simulation

Based on processes chain simulation technology, a gradually added filler element method was applied for modeling multi-pass welding and the simulation was achieved step by step with coupled thermal-mechanical finite element method. A research part of multi-pass welding was simulated by both the chain simulation technology and the traditional method. To compare the two simulations, convergence for the chain simulation technology is better and its results of longitudinal residual stresses are more accuracy. Meanwhile, the stress evolution history under the thermal-mechanical activities of multi-pass welding was analyzed, and the principle of longitudinal stresses changing under multi-thermal cycles was revealed.