STRETCH-FLANGE CRACK PREDICTION METHOD, STRETCH-FLANGE CRACK PREDICTION DEVICE, COMPUTER PROGRAM, AND RECORDING MEDIUM

摘要

This stretch-flange crack prediction method for predicting occurrence of stretch-flange cracking at a flange end part when stretch-flange forming is performed on a plastic plate, wherein the method is provided with: a measured value acquisition step (S1) for acquiring a breaking strain measurement, vertical strain gradient measurement, and a circumferential strain gradient measurement for each of a plurality of plate-shape specimens; a CAE analysis step (S2) for acquiring a largest maximum principal strain element in which the maximum strain is the largest, the vertical strain gradient of the largest maximum principal strain element, and the circumferential strain gradient of the largest maximum principal strain element; a breakage determination threshold value acquisition step (S3) for converting the breaking strain measurement to acquire a breakage determination threshold value; and a prediction step (S4) for predicting the occurrence of a stretch-flange cracking when the maximum principal strain is equal to or greater than the breakage determination threshold value.