Thermal and structural analysis of laser beam machining process on a Dual Phase 780 (DP780) workpiece

This study highlights the development of an intelligent thermo-structural model for precise prediction of responses such as the width of heat-affected zone (HAZ), equivalent stress and total deformation for laser beam machining (LBM) process while machining a novel Dual Phase 780 (DP780) workpiece. The numerical model is analyzed through response surface Box-Behnken design to study the consequences of input parameters such as voltage (V), current (I) and cutting speed (N) on the above-mentioned response parameters. The results achieved through the numerical model are validated by comparing them with experimental results. Furthermore, a careful parametric study along with line and surface plot analysis is conducted to evaluate both linear and quadratic relationships between the input and the response parameters, respectively. The results indicate that the HAZ can be reduced significantly through efficient laser processing with optimum input parameters. The process parameters are optimized by developing an objective function for each of the response parameters through regression analysis. An extremum model is used to obtain the ideal values of HAZ, equivalent stress and total deformation. These results are also validated by conducting a confirmative test using the numerical simulation model which is validated through experiments.