Evaluation of creep-fatigue design methods by structural failure tests under thermal loads Original Research Article

Creep-fatigue tests were conducted under cyclic thermal stresses using two types of simple structural models, the free surface model and ring cylinder model. All models were made of SUS304 stainless steel and some of the specimens had longitudinal welds. Failure lives were defined as the cycle at which small visible cracks were detected. Three kinds of life evaluations were made. Two of these were based on elastic analysis and one of these was based on inelastic analysis. The estimated lives were compared with the experimental results and the results can be summarized as follows. 1. (1) Life estimation based on inelastic analysis was adequate and the estimated lives agreed well with the experimental results. 2. (2) Life estimation by the Monju Design Guide based on elastic analysis gave conservative results. However, the accuracy of life estimation could be improved by using the elastic follow-up factor (q value) obtained from inelastic analysis.