Numerical simulation of the laser welding process in butt-joint specimens

A three-dimensional finite element model has been developed to simulate the laser welding process and predict laser welded panel distortions. The finite element calculations were performed using the SYSWELD FE code, which takes into account thermal, metallurgical and mechanical aspects. The simulation of the laser welding process was performed using a nonlinear heat transfer analysis, based on a keyhole formation model, and a coupled transient thermo-mechanical analysis. The analysis takes into account metallurgical transformations using the temperature dependent material properties and the continuous cooling transformation (CCT) diagram. The geometry examined was a butt-joint specimen that consisted of thick AH36 shipbuilding steel plates, using different welding parameters. Experimental testing was carried out to measure the distortions of the welded specimens and verify the FE approach. The FE results are in good agreement with experimental measurements.