Elastoplastic Finite Element Analysis and Fatigue Life Prediction for Notched Specimens under

Biaxial Cyclic Loading

SUN Guoqin¹  SHANG Deguang¹  CHEN Jianhua²  DENG Jing¹

(1. College of Mechanical Engineering and Applied Electronics Technology, Beijing University of Technology, Beijing 100022;
2. Department of Mechanical Engineering and Electronics Technology, Handan Polytechnic College, Handan 056001)

Abstract: An elastoplastic finite element analysis is adopted for thin tubular and notched specimens under biaxial proportional and nonproportional tension-torsion loading at high temperature. Elastoplastic material property is described by the Von Mises yield criterion, the multilinear kinematic hardening rule and uniaxial cyclic stress-strain data under high temperature. Tension-torsion loading with strain controlling is carried out by applying the axial and circular displacement on one end of the specimen in the cylindrical coordinate system. The method is proved suitable by comparison between FEA and experimental results. Then the elastoplastic finite element method is used to the notched specimens. The local cyclic stress-strain responses at notch root are obtained. Fatigue crack initiation life is predicted on the basis of the local stress-strain data with Kandil-Brown-Miller and Smith-Watson-Topper models.

Key words: Notch  Elastoplastic finite element method  Biaxial fatigue  Life prediction

CLC No: O346.2

国家自然科学基金(10172010)和北京市人才强教计划资助项目. Received 2007 20070312, received in revised form 20071024