【摘要】 塑性成形过程中,材料的韧性断裂是主要约束因素之一。本文采用实验与有限元结合的方法,对几种有代表性的韧性断裂准则进行了分析。结果表明以孔洞理论为基础的Oyane断裂准则能够较准确的预测成形中的启裂位置,与实验结果相吻合。同时将Oyane断裂准则用于预测冷镦内六角螺钉过程中的开裂,结果与实际生产相符合。更多还原

【Abstract】 An important concern in metal working proces is whether the desired deformation can be accomplished without failure of the material.This paper describes the utilization of ductile fracture criteria in conjunction with the finite element method so as to predict surface and internal failures in cold metal working proces.Four previously published ductile fracture criteria are selected and their relative accuracy for predicting and quantifying fracture initiation sites is investigated.The result implies that: Oyane ductile fracture criteria,based on void growth model,can successfully predict the position in which fracture start,and has a good agreement with the experiments.What’s more,Oyane ductile fracture criteria can be also used to predict the fracture of socket head screws in cold heading.Resulting in a good agreement with the practice as well.更多还原