摘要
表征应力状态参量的应力三轴度是控制材料断裂模式的关键因素,所以应力三轴度作为影响材料的断裂因素而被引入到众多失效模型中。利用有限元辅助测试(Finite element Aided Testing,FAT)方法来获取材料等效全程单轴本构关系,进而获取漏斗型试样在拉伸过程中根部截面上的应力三轴度演化情况,并同根据Bridgman应力修正后的单轴本构关系得到的应力三轴度分布进行了对比分析。结果表明,基于Bridgman应力修正得到的应力三轴度与有限元计算结果相差较大。基于应力三轴度分析,讨论了漏斗型试样的破断机理,给出了四种延性材料的等效全程单轴本构关系、破断应变、破断应力和漏斗根部截面的应力三轴度分布随截面中心von Mises等效应变的变化规律。
Stress triaxiality is a key factor in controlling the fracture of materials. Based on new method of finite element aided testing（ FAT）,the full-range constitutive relationship of ductile materials could be obtained. Thus,the distribution and evolution of stress triaxiality at the root of a funnel specimen is able to be obtained by ANSYS APDL program. The comparison of the analyzed results with those obtained by Bridgman correction method is completed and the failure mechanism of funnel-shaped specimen is discussed. The full-range constitutive relationship,fracture stress,fracture strain of the four ductile materials are given. Therefore,the law of the distribution and evolution of stress triaxiality at the root of funnel-shaped specimens are investigated.
出处
《机械强度》
CAS
CSCD
北大核心
2015年第6期1152-1158,共7页
Journal of Mechanical Strength
基金
国家自然科学基金项目(11202174)资助~~
关键词
应力三轴度
单轴全程本构关系
FAT方法
颈缩
破断
Stress triaxiality
Full-range constitutive relationship
FAT method
Necking
Fracture
