Numerical and experimental investigation of the effect of heat input on weld bead geometry and stresses in laser welding

Abstract

Nowadays, laser welding is a powerful joining method. Thanks to the advantages it has, its usage area is increasing day by day. However, getting the desired result from the laser welding process is possible with the proper welding parameter selections. Otherwise, many problems may be encountered, including significantly incomplete penetration. For this reason, parameter selection has been discussed in many studies in the literature. At this point, validated numerical simulation models are precious. Since these models reduce experiment costs and save time. Especially numerical simulation of the structural steel, which is the one of most used materials, is crucial. In this study, the effects of laser power (LP) and welding speed (WS), which are among the vital parameters of laser welding, on weld width and stress were investigated numerically and statistically. Structural steel was selected as the material, and the Taguchi method was carried out for the simulation case study design. Simufact Welding software was used for simulation studies, and simulations were carried out thermomechanical. Thus, more realistic results were obtained via the thermomechanical method. One of the simulation results was verified through an experimental study. The results were evaluated with signal-to-noise (S/N) ratio and a statistical analysis of variance (ANOVA), and as a result of the study, it was seen that the welding speed was a more effective parameter, the optimal parameter combination was found to be 3500 W for laser power and 40 mm/s for welding speed to get maximum weld width and minimum equivalent stress. In addition, it was observed that correctly created simulation studies may provide very close results to experimental studies.