Multi-objective calibration of the double-ellipsoid heat source model for GMAW process simulation

The scope of application of simulation models in welding is limited by the accuracy of their output results. This paper presents a calibration procedure for a 3-D quasi-stationary model of heat transfer for gas metal arc welding. The double-ellipsoid heat source used in this model has five input parameters whose value cannot be specified accurately. To estimate these values, we employed a multi-objective calibration procedure with two objective functions using the paretosearch optimization algorithm. Objective functions represented the error between simulated and experimentally observed values of penetration depth and weld bead width during gas metal arc welding of P355GH steel plates. All input parameters were assumed to be a power function of line energy. To reduce computational time, we replaced the numerical model with a response surface methodology metamodel based on an optimal set of simulation results from the numerical model. The results of the simulations based on calculated values of input parameters for the heat source model showed excellent matching with the experimental results.