FEM DISTORTION MODEL DURING THE LASER WELDING PROCESS WITH FILLER MATERIAL FOR THE EFFICIENT PRODUCTION OF LARGE WELDED PARTS

Abstract

Laser welding is most of the times chosen because of its capability for providing low distortion in the part. However, thermal expansion and contraction cycles during the joining process must be taken into account, since they can cause deformations. For minimizing the distortions caused by the weld bead, the optimization of welding sequences is essential, although it is time- and resource-consuming. Therefore, deformation prediction by employing finite elements (FEM) is one of the solutions that have been employed in recent years.
In this research it is proposed to develop a model capable of predicting the simulation of structures with thicknesses of approximately 5 mm by means of simplified methods. Simplified methos are employed because the conventional analysis of thermomechanical FEM models is difficult to use in large welds due to the excessive calculation time. In parallel, the optimization of the laser welding process is carried out by studying the input parameters and results. In addition, an in-situ monitoring system is included to measure the deformations during the welding process, feeding these measurements to the FEM model. Finally, the simulation of the calibrated model is carried out for a real structure of larger size.