Analysis of the effect of an electrically conductive die on electromagnetic sheet metal forming process using the finite element-circuit coupled method

Accurate calculation of electromagnetic parameters in electromagnetic forming (EMF) process is crucial for predicting the deformation behavior of metallic workpieces. Previous theoretical and numerical studies for EMF process with a die have assumed that the die near the workpiece is non-conductive. However, the simplified treatment could be invalid for the cases with a conductive die since an eddy current would also be induced in the die under transient magnetic fields, thus resulting in the change of electromagnetic force acting on the workpiece. In this work, a coupled finite element method and circuit simulation approach with an improved circuit model for analyzing the workpiece deformation is presented, in which the mechanical analysis of the workpiece is done using ANSYS, while the circuit analysis is performed using an improved current filament model. Numerical simulations have been carried out for two types of EMF process, revealing the potential effects of an electrically conductive die on the electromagnetic force distribution and workpeice deformation. The coupled modeling method and simulation results could be useful for better understanding EMF process and designing EMF systems.