韧性断裂准则在板料成形中应用研究进展

对板料成形中的成形极限应力图、最大变薄率、成形极限图以及韧性断裂准则等预测成形极限的方法进行了综述和分析,提出了利用韧性断裂准则能够较好地预测塑性差的板料成形极限,而且还能考虑应变路径的变化.利用有限元方法模拟时,韧性断裂准则既可以运用到完全耦合的弹塑性损伤模型的增量方法中,也可以运用到一步有限元逆算法中.指出了为准确地预测成形极限,除了提高有限元模拟精度外,应找到一种本质地反映材料性能的准则.

Recent research advance of application of ductile fracture criteria in sheet metal forming process

The paper overviews the methods of predicting the forming limit stress diagram in sheet metal forming,the maximum forming ratio,the forming limit diagram,the ductile fracture criteria(DFC),and so on.Making use of DFC,the forming limit can be predicted in the metal sheet with low ductility,and can be predicted when the forming path varies.In the finite element method,DFC can be applied to incremental approaches with a fully coupled elastoplastic-damage model,and can be applied to the one-step inverse approach.In order to predict the forming limit exactly,a criterion that indicates the material ability in essence is expected to be worked out,including the improvement of finite element method.