Method for evaluating deformation limit on shearing surface of metal sheet, crack prediction method, and design method for press mold

摘要

It provides a method for evaluating cracks by bending in a section of a sheared platen and a prediction method, and provides a technique to be reflected in the design method of a press mold. It is a method of evaluating the strain limit for evaluating the strain limit in the shear working surface 10A of the metal sheet 1 when press-molding the sheared metal sheet 1. Of the distribution of distortion occurring near the boundary between the bending outer surface of the metal plate 1 subjected to bending and the shearing surface 10A, the surface distortion distribution in the thickness direction X of the shearing surface 10A at the evaluation position The gradient and the index value obtained from the gradient of the two surface distortion distributions of the gradient of the surface distortion distribution in the bending ridge direction Y by the bending direction toward the direction away from the shearing surface 10A and the tension generated on the shearing surface Based on the relationship, the strain limit at the shearing surface 10A is evaluated or cracks are predicted.