Cai Lixun1,Ye Yuming1,Gao Qing1,Li Cong2
(1.Department of Applied Mechanics and Engineering,Southwest Jiaotong University, Chengdu 610031,China;2.National Key Laboratory for Nuclear Fuel and Material,Nuclear Power Institute of China,Chengdu 610041,China)
Abstract:A series of strain fatigue tests on small slice specimens with 1-2 mm thickness of Zr-4 alloy were conducted. According to experimental analysis and EPFEA(Elastic and Plastic Finite Element Analysis),concepts of elasticª²plastic shape factors and equivalent Poisson's ratio were presented.An equivalent strain method resulted from EPFEA was developed to transform transverse strain of bugle-specimen to uniaxial strain,and two simplified equivalent strain equations were recommended.By the new equivalent strain equations,M-C£¨Mansonª²Coffin£©fatigue models of Zr-4 alloy were obtained based on the strain fatigue test results of Zr-4 alloy. The results show that for small slice specimen,the life prediction resulted from the traditional method has quite large safe factor.However,the life prediction resulted from the present two simplified equivalent strain methods have reasonable safe factor,ranging from 1 to 2 times.
Keywords:zircaloy alloy;strain fatigue;shape factor;life estimation;finite element analysis