Assessment of σd approach for creep damage estimation of FBR components with crack like defects at welds

The creep damage estimation procedure provided in RCC-MR: Appendix A16 which is based on the σd approach, is investigated by predicting the creep crack initiation life of two pre-cracked standard CT specimens machined from welded austenitic stainless steel plates, subjected to constant axial loading. The analysis indicates that the present version of A16 over-predicts the life. Hence, modifications are suggested for A16 including the effects of the hydrostatic stress component, after numerical investigation. The improved procedure predicts the experimental creep initiation life reasonable closely. Based on the investigations, RCC-MR: A16 may consider the revised procedure to estimate the creep damage of structures with geometrical singularity.