In order to investigate crack propagation behavior of thermal fatigue on the basis of non-linear fracture mechanics crack propagation tests were conducted for isothermal fatigue at several temperatures and for cyclic temperature fatigue. The results obtained were summarized as follows (1) The fracture mechanics laws in isothermal fatigue dl/dN- DELTA J//f and dl/dN- DELTA J//c relations where dl/dN was crack propagation rate, DELTA J//f was fatigue J-integral range and DELTA J//c was creep J-integral range) showed little dependence on temperature. (2) A simple evaluation method of the values of DELTA J//f and DELTA J//c in thermal fatigue was proposed. (3) Crack propagation under cyclic temperature could be divided into two types which were cycle-dependent and time-dependent. dl/dN had good correlations with DELTA J//f and DELTA J//c for each type, respectively. (4) The transient condition between two types was given by a function of DELTA J//f and DELTA J//c. (5) The same fracture mechanics law were obtained in isothermal and cyclic temperature fatigue.
|Number of pages||7|
|Journal||Nippon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A|
|Publication status||Published - Jun 1987|
ASJC Scopus subject areas
- Mechanical Engineering