Creep-fatigue defect assessment test and analysis of high temperature structure

The creep-fatigue damage evaluation and the defect assessment are the one of key parameters to ascertain the structural integrity of high temperature structures. In this study, the creep-fatigue test with geometrically nonlinear structure including through wall defects was performed to examine the structural integrity of the defect structure and to validate the inelastic analysis code NONSTA. The creep-fatigue damage was examined by a portable zoom microscope and the replication technics allowed to observe the structure surface. After 400 cycles of testing, no apparent creep-fatigue was observed except the defect front. At the defect front, creep-fatigue crack initiation was observed. The commercial finite element analysis softwares ANSYS and ABAQUS were used for the corresponding structural analysis. Both elastic analysis and inelastic analysis using NONSTA code were performed with collected temperature profile from the test and the strain results of analyses agree well with those from the test. The creep-fatigue damage was assessed per ASME-NH utilizing analysis results and the creep-fatigue crack initiation was assessed per RCC-MR A16. The results show good agreement between analysis and test