Creep life prediction of Ni‐based single‐crystal superalloy plate with film‐cooling holes using a modified critical distance method based on the improved weight function

Abstract

This paper proposed a new weight function modified critical distance method to predict the creep life of Ni‐based single‐crystal superalloy plate with film‐cooling holes through experimental and numerical research. The creep test and numerical simulation results both indicated that cracks originated around the hole, and the location of the maximum Mises stress point around the hole was consistent with the crack initiation point shown in the test results. Considering the stress gradient in the thickness direction, a critical fracture surface was defined, and the stress distribution at the critical fracture surface was defined using polynomials. An improved stress gradient function and weight function were introduced to calculate the effective stress at the critical fracture surface. The effective stress was used to predict the creep life of the plate with film‐cooling holes. Compared with the experimental results, the errors were all within the dispersion band of 1.5 times, indicating good prediction results.