In magnetic pulse welding, the deformation occurring when a moving sheet collides with a fixed sheet is analyzed following a free deformation analysis of the moving sheet, and a magnetic pressure is used as an input of the moving sheet. In the free deformation analysis, the initial magnetic pressure is calculated for the moving sheet standing still, and the pressure applied to the sheet deforming is renewed by the method of successive approximation. Consequently, the time and velocity calculated at the first collision can be close to the measured values of the standard, and the calculated values are used as the initial values in the deformation analysis with collision. An equivalent stress in the fixed sheet is distributed in a semi-ellipse shape at the early stage after the first collision because the moving sheet deforms in a convex shape. After that, the moving sheet and the fixed sheet vibrate to repeat contacts and separations. As a result, the center of a weld sheet fabricated finally becomes the non-joining. The moving velocity and collision angle at a collision point, which are the joining condition, become constant with time because of the vibration of the two sheets.
Itoi et al. (Tue,) studied this question.