Temperature effect on electromagnetic forming process by finite element analysis

Abstract

In the electromagnetic forming (EMF) process, the Lorentz force is generated by the repulsive interaction of magnetic field between a pulse transient current in a coil and an eddy cu rrent in a workpiece. During the process, the current will generate Joule heat in both the coil and workpiece raising their temperatures. The objective of this work is to build a coupled analysis to consider the temperature effect during the electromagnetic sheet metal forming process by using a finite element anal ysis. During the analysis, the electromagnetic, mechanical and temperature problems are considered simultaneously. Then, the coupling effects of the temperature with eddy currents, magnetic fields, magnetic force density, and deflection of the sh eet metal are discussed. The results indicate that the temperature in creasing is significant especially during repeated working cycles, and the deflection of a sheet metal is reduced as the increasing of the coil temperature. Hence, this temperature effect shoul d be considered to avoid the failing of products and to improve the life of the forming coil, especially in a mass production pr ocess.