| Electromagnetic Forming (EMF) is a high strain rate process where the effect of temperature gradients becomes important and where the generation of heat during plastic deformation should be recognized. A commercial finite element analysis (FEA) software, ANSYS, is used to simulate the EMF process by means of a sheet metal impinging on a die at high speed and deforming to the final shape, in this case, a cup. It is assumed that this process is a bending and stretching process. ANSYS' shell and contact elements have been used to model the sheet metal and its contact with the inside surface of the die, and thus gradually deform the sheet to its final shape by high inertia forces. It is known that in high energy rate forming processes, such as EMF, the high energy will promote strain localization and premature failure in regions of high strain rate. Therefore, the choice of the optimum speed to deform the sheet to a degree that will not cause local failure and at the same time deep-form the material is very important.; In order to avoid local failure due to thermal softening, the highest temperature should be below 200{dollar}spcirc{dollar}C for the aluminum alloy chosen in this simulation. The results show that at this highest temperature, the corresponding maximum deformation is approximately 2.0 cm and the highest strain rate will be 200 m/s, which matches well with the data recommended in the literature (230m/sec).; The analysis also shows that this process is only suitable for forming a shallow cup. Hence, it is recommended that the sheet metal be shallow-formed several times to obtain a final deep cup, on the condition that the final deformation of the sheet is within the forming limit. |
