基于局部法对预应变下高强钢断裂韧性预测研究

he tension and fracture toughness tests on high-strength steel Q420 were carried out under different conditions. The local parameters m and σu controlling brittle fracture were obtained using FEM analysis and WSTRESS program. It was certified that the critical Weibull stress conform to two-parameter Weibull distribution. The fracture toughness of specimen with prestrain was predicted from the virgin material test results based on the local approach, and prediction was consistent with the experimented results. It indicated that the fracture behavior of the material with prestrain was characterized well.