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

摘要

In order to prevent the occurrence of cracks in the sheared end face due to press forming, a technique for evaluating and predicting the cracking limit of the sheared end face of the metal plate and determining the press forming conditions is provided. A method of evaluating a deformation limit at a shear end face of the metal plate (1) when the metal plate (1) subjected to shearing is deformed by press forming, wherein the metal plate (1) is formed by press forming. In the stress distribution generated near the shear end face in (1), the deformation limit is determined by an index value obtained from two stress gradients at the evaluation position, a stress gradient in the thickness direction X and a stress gradient in a direction away from the shear end face. To evaluate.