A coupled electric–magnetic numerical procedure for determining the electromagnetic force from the interaction of thin metal sheets and spiral coils in the electromagnetic forming process

In this paper, a numerical procedure is proposed that is both coupled electromagnetic and uncoupled magnetic-mechanical, and enables the calculation of electromagnetic force in thin circular flat plates by using a spiral coil as an actuator. Its inductances, which link the electric and magnetic phenomena, can be calculated by treating the problem as an electric circuit. The influence of system parameters, such as pulse energy, workpiece and coil geometry and material properties, are considered in the calculation of electromagnetic force. The calculation routine models the problem as a system of ordinary differential equations to obtain the discharge (actuator coil) and induced (workpiece) currents. Free bulging experiments with discharge current acquisition were performed to demonstrate satisfactory correlation with the calculation method, which provides valuable feedback for system design.