Abstract: The theory research on electromagnetic forming is related to electromagnetics and plasticity dynamics. Of all the problems, magnetic pressure calculation is the basic one. FEM (Finite element method) is an effective method in enhancing the accuracy of magnetic pressure calculation. But for the FEM, how to confirm the solving area and magnetic field charac- teristic on the boundary is the key problem. The symmetry of magnetic field characteristic in the condition that workpiece and forming coil are placed coaxially is calculated by analysis. According to the result of magnetic field characteristic, the solving area of FEM is decided and the magnetic field characteristic on the boundary is presented. Then, the magnetic field and magnetic pressure distribution of solenoid coil and echelon coil are simulated by means of FEM and the magnetic pressure distribution is verified by electromagnetic bulging experiment.

Key words: Electromagnetic bulging, Finite element method, Magnetic field characteristic, Magnetic pressure distribution