Calculation of electromagnetic force in electromagnetic forming process of metal sheet

Abstract

Electromagnetic forming (EMF) is a forming process that relies on the inductive electromagnetic force to deform metallic workpiece at high speed. Calculation of the electromagnetic force is essential to understand the EMF process. However, accurate calculation requires complex numerical solution, in which the coupling between the electromagnetic process and the deformation of workpiece needs be considered. In this paper, an appropriate formula has been developed to calculate the electromagnetic force in metal work-piece in the sheet EMF process. The effects of the geometric size of coil, the material properties, and the parameters of discharge circuit on electromagnetic force are taken into consideration. Through the formula, the electromagnetic force at different time and in different positions of the workpiece can be predicted. The calculated electromagnetic force and magnetic field are in good agreement with the numerical and experimental results. The accurate prediction of the electromagnetic force provides an insight into the physical process of the EMF and a powerful tool to design optimum EMF systems.

Continuous Casting of Thin Aluminum Strips Using the Electromagnetic Levitation

“…A validation has shown there is not necessary to use a visual assignment of values from experimentally attained curves H-a. It is more advantageous to employ the accurate calculation of H-a values which is based on interactions between the inductor and its mirror image known from the theory of induction heating [11,12] and electromagnetic forming [19].…”

An Analysis of Electromagnetic Sheet Metal Forming Process

“…This results in constants mutual inductances between the disk and coil, throughout the forming process. Since the electromagnetic force is very fast, this simplification is valid [6]. By neglecting the variations of the mutual inductances during the forming operation, the transient electrical problem can be separated in a RLC primary circuit coupled with n secondary RL…”

“…We assume that the electromagnetic force duration is short compared with the whole deformation time, and the effect of the metal sheet displacement is less significant than other EMF conditions, such as tube compression and expansions. Besides that, it has been reported that most of the sheet deformation results from the inertia forces due to the pulse of electromagnetic force [6].…”

Analytical solution for the diffusion of a capacitor discharge generated magnetic field pulse in a conductor

“…5 Since this pressure is all that matters in electromagnetic forming, the details of the field distribution appear to be little studied. An analytical model 6 of the magnetic field diffusion in the process of electromagnetic forming has been proposed recently. The solution is sought in form of decaying oscillations.…”