Distributions of temperature and stress fields on penetration assembly during multi-pass welding

Welding is a fundamental manufacturing technique used to join metal components. They cause errors during the assembly of the structure and reduce the strength of the structure. Based on an elastic-plastic-model, a three-dimensional finite element numerical simulation of a stainless steel penetration assembly during multi-pass welding with girth welds is carried out in this paper. And then the transient temperature field and the real-time dynamic stresses field of the structure are obtained. The heat source is modeled as a moving heat flux along girth welds following a double ellipsoid distribution. The 'birth and death' element method is applied to simulate the gradual growth of welding pass metal. The way of predicting the residual stresses in this paper can prepare an error-minimizing guide at design stage and can be used in accuracy management.