Deformation limit evaluation method, crack prediction method and press die design method

摘要

To provide a technique for predicting bending crack limit of a sheared surface of a metal plate and determining press molding condition in order to prevent occurrence of bending crack of the sheared surface.SOLUTION: A deformation limit evaluation method for evaluating deformation limit in a sheared surface 10 of a metal plate 1 when performing press molding including bending deformation for the sheared metal plate 1. A relationship between a bending radius R of a bending part due to bending deformation, which is given to a part including the sheared surface 10 of the metal plate 1, and a crack length L generated on the sheared surface 10 is determined. From the determined relationship between the bending radius R and the crack length L, bending deformation limit of the metal plate 1 at the part including the sheared surface 10 is evaluated.SELECTED DRAWING: Figure 2