Multiple Cracks Interaction Model and Residual Life Assessment Methods for the High-Temperature Structure

Multiple cracks are often found in many high-temperature structural components. The interaction and coalescence of multiple cracks may significantly influence the service lives of these high-temperature components. The interaction effect on multiple cracks is investigated under creep conditions in this paper. The results indicated that interaction of multiple cracks is different between the time dependent fracture characterized by C*-integral and linear elastic fracture noted by SIF. The level of conservatism of the current alignment rule was discussed under creep conditions. Then combination rules and regularization of multiple cracks under creep conditions are developed. Based on these analyses, the assessment method for the residual life prediction of high-temperature structure containing multiple cracks is developed.