Application of gas metal arc welding process model to computational welding mechanics

Abstract

In this study, a new integrated simulation methodology has been proposed for the more accurate numerical simulation of weld distortion generated by gas metal arc welding. The integrated simulation model of gas metal arc welding was constructed by coupling between welding process and mechanics. The welding process models consist of arc plasma (heat source) model and bead formation (process) model. In the arc plasma (heat source) model, computational simulation based on mathematical modeling of the heat transfer from arc plasma to a welded plate is performed to obtain a more precise properties of heat source from welding heat input conditions. In the bead formation (process) model, computational simulation based on a coupling analysis between weld bead balance and thermal conduction is performed to obtain a more precise temperature distribution and weld bead configuration during welding from the properties of heat source obtained. In the stress and distortion (mechanics) model, computational simulation based on a large deformation thermal elastic-plastic analysis is performed to obtain a more precise weld distortion from the temperature distribution and weld bead configuration obtained. Through the developed simulation technique, weld distortion becomes to be available almost exclusively from welding heat input and process conditions. A bead-on-plate welding of high strength steel was performed under the same welding heat input and process conditions to compare the simulation results with the experimental results. It was concluded that both results of angular distortion were in extremely good agreement and thus the developed simulation technique has the potential to become useful for a highly accurate predictive simulation of weld distortion.