Numerical Simulation of Laser Beam Welding of Stainless Steel and Copper Butt Joint

The paper aims to design a simulation of a butt weld made of stainless steel and copper by a laser beam. The concept of the problem solution is based on a non-experimental method of thermomechanical and stress-strain analysis of the laser welding process of dissimilar materials, which can largely predict suitable welding parameters for real experiments and thus effectively reduce welding defects. All simulation steps were performed using ANSYS simulation software. A Gaussian volumetric heat source was used for the simulation. The physical and mechanical properties of the materials are temperature dependent and must be defined in the simulation software. The ANSYS SpaceClaim module was used to create the geometric model. The geometric model is dimensionally identical to the sample used in the real experiment. The initial conditions in the numerical simulation were determined based on the initial state of the experimental sample. Real samples were welded using a disk laser; parameters were set based on simulation. The results of the thermal analysis are used to examine the temperature fields created in the welding process. They are used to optimize welding parameters. According to experimental and simulation results, there is a different maximum temperature in the weld metal on the copper side as well as on the steel side due to a higher coefficient of thermal conductivity of copper. The results of the stress-strain analysis consist of two parts. The first part examines the effect of clamping on the stresses arising in the welding process, and the second part is focused on the overall deformation. Due to the small differences in the values of the coefficient of thermal expansion of the metals used and the small dimensions of the test specimens, the residual stresses and strains are negligible.