Numerical Simulation and Experimental Study of Electromagnetic Forming

Compared to traditional sheet metal forming, electromagnetic forming (EMF) has several advantages, such as increased formability, cost savings and improved flexibility. There are many EMF applications in sheet meal forming, especially for aluminum alloys, because aluminum alloys have relatively low formability and high conductivity when compared to steel. The EMF process uses magnetic field generated by a conductive actuator upon large capacitor discharge to accelerate workpiece to high velocity. It is a complex coupled mechanical-thermal- electromagnetic phenomenon, which makes it difficult to numerically simulate. However, to save time and cost, numerical simulation is needed to accurately predict results of EMF. The Electromagnetism (EM) module of LS-DYNA® has been developed by LSTC, which can be used for numerical simulation of EMF. American Trim has applied this module to assist in its EMF designs. In this paper, to access the capability of EM module, the numerical and experimental results of sheet metal formed with EMF were compared. The experiment was to apply EMF for straight-edge flanging of Al 6061-T6 sheet. Then this flanging process was modeled using both SMP and MPP version of LS-DYNA EM module. The comparison between the final shapes of flanged samples and the numerical simulation showed the good correlation between experimental and numerical results, which indicates the good predictive ability of the LS-DYNA EM module for EMF.