Research on fatigue failure mechanism and life prediction method of FGH96 flat plate with a hole

Fatigue tests were conducted on FGH96 flat plates containing a hole at 600 ℃. Utilizing a viscoplastic constitutive model, the stress and plastic strain distributions within these plates were meticulously calculated. Scanning electron microscopy（SEM） was employed to analyze the fatigue failure mechanism. Based on SEM observations and the geometric attributes of the FGH96 plates with holes, the critical fatigue damage and stress concentration coefficient were defined. Subsequently, the CDM（cumulative damage model）was refined accordingly. The findings revealed that, in comparison to conventional fatigue life prediction techniques, the revised CDM model, which incorporates critical fatigue damage and stress concentration coefficients, exhibited enhanced prediction accuracy for the fatigue life of FGH96 flat plates with holes. Notably, all prediction results fell within a ±2 error band.