Two Models for Predicting Fatigue Crack Growth
In this investigation two fatigue crack growth models based on the different physicalassumptions were systematically analyzed.One model makes use of the size of the stable damagedistribution zone near crack as the major contributor to the fatigue crack growth.This model is basedon the concept that a material point failures and a new crack will form when the fatigue damage valueof the material point reach the critical damage.The other model supposes that fatigue growth can bedescribed as a process with sequentially breaking small volume elements behind the crack tip.Thefatigue crack growth can be regarded as successive crack re-initiation over a critical distance.Thefatigue crack growth rate can be determined as the ratio of the critical distance to the average lifewithin critical distance.Both models use macro parameter to describe the microscopic mechanism.An elastic-plastic finite element analysis (FEA) was used to obtain the detailed stress-strain history ofthe notched component with a detailed consideration of the cyclic plasticity of the material using arobust cyclic plasticity model.The fatigue damage distribution and the average damage within thecritical distance near the crack tip can be obtained by combining the fatigue damage parameter withthe stress strain distribution from the finite element analysis.These two models were evaluated usingthe experimental results obtained from the crack grow experiments on compact specimens made from16MnR.The predicting results using these two models correlate well with the experimental data.Theresults show that two models can well describe the notch effect on the fatigue crack growth.
Cyclic plasticity fatigue crack growth fatigue criterion damage distribution
B.X.Qiu Z.L.Gao L.J.Lu X.G.Wang Y.Y.Jiang
Zhejiang University of Technology,The MOE Key Laboratory of Mechanical Manufacture and Automation,Ha University of Nevada,Reno,Department of Mechanical Engineering (312),Reno,NV 89557,USA
国际会议
成都
英文
2008-08-04（万方平台首次上网日期，不代表论文的发表时间）