Assessing Fatigue Life Cycles of Material X10CrMoVNb9-1 through a Combination of Experimental and Finite Element Analysis

Abstract

This paper uses a two-scale material modeling approach to investigate fatigue crack initiation and propagation of the material X10CrMoVNb9-1 (P91) under cyclic loading at room temperature. The Voronoi tessellation method was implemented to generate an artificial microstructure model at the microstructure level, and then, the finite element (FE) method was applied to identify different stress distributions. The stress distributions for multiple artificial microstructures was analyzed by using the physically based Tanaka–Mura model to estimate the number of cycles for crack initiation. Considering the prediction of macro-scale and long-term crack formation, the Paris law was utilized in this research. Experimental work on fatigue life with this material was performed, and good agreement was found with the results obtained in FE modeling. The number of cycles for fatigue crack propagation attains up to a maximum of 40% of the final fatigue lifetime with a typical value of 15% in many cases. This physically based two-scale technique significantly advances fatigue research, particularly in power plants, and paves the way for rapid and low-cost virtual material analysis and fatigue resistance analysis in the context of environmental fatigue applications.

Modeling Metallic Fatigue Data Using the Birnbaum–Saunders Distribution

“…Fatigue-life prediction is vital to prevent the failure of mechanical parts that are under cyclic loadings. In the field of fatigue-life assessment, two primary methodologies are commonly used: stress-life models (or S-N curves) [1][2][3][4] and linear elastic fracture mechanics (LEFM) [5][6][7][8]. The S-N curve method relies on experimental data that models stress amplitude against the number of cycles until failure.…”