Surrogate model building and error analysis for the damage tolerance life of penetration type fatigue crack

Abstract

The penetration type cracks are often found in the components of mechanical systems and are a major threat to the operational reliability of mechanical components. There are many factors affecting the fatigue crack damage tolerance life, so the numerical calculation of 3D fatigue crack propagation is a complex process. Therefore, it is significant to improve the calculation efficiency of fatigue crack life with guaranteeing the calculation accuracy. The crack life is the result of the integration of crack propagation length and stress intensity factor(SIF). In this paper, a surrogate model for calculating the damage tolerance life of penetrating fatigue cracks is constructed using Kriging method based on the results of experimental tests and finite element analysis(FEA). The surrogate model is a four-dimensional response-value solution model, which can solve the fatigue crack life under random parameters. Finally, an error analysis is performed on the results of the surrogate model calculation. The results indicate that the error of the surrogate model calculation is relatively low, and the overall error is within 2%. Therefore, the surrogate model is characterized by high efficiency and accuracy.