Using Triaxiality Dependent Cohesive Zone Model in Low Cycle Fatigue
Cohesive zone models (CZM) are widely used for material fracture analysis.In monotonic loading process,the cohesive parameters are remarkably dependent on the specimens triaxiality conditions.A cyclic CZM is now introduced for crack initiation life and fatigue crack growth analysis.These two types of fatigue phenomena-crack initiation and fatigue crack growth-are to be described by the cyclic CZM with a unique set of parameters.Fatigue crack initiation is usually investigated using smooth specimen and fatigue crack growth is measured using compact tension specimen.The triaxiality condition in the CZM of these two standard specimens is strongly different.Realistic modelling of the phenomena therefore requires taking the triaxiality into account in the damage evolution law of the cyclic CZM.As a consequence in this paper a cyclic CZM combined with triaxiality dependent characteristic is proposed.This new model can be applied for specimens with different triaxiality conditions.The computation results including crack initiation life and fatigue crack growth simulation are compared with experimental data.In the very low cycle fatigue regime,a reasonable accordance of experimental and calculated results is achieved.
Cohesive zone model Triaxiality dependence Low cycle fatigue Damage evolution
Xuan Cao Michael Vormwald
Material Mechanics Group,Technische Universit(a)t Darmstadt,64287 Darmstadt,Germany
国际会议
北京
英文
1-10
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）