Statistical analysis methods of fatigue crack growth rate

Abstract

The standard center-cracked tensile specimens M(T) with different widths made of aluminum alloy were designed for fatigue crack growth rate experiments, and the effect of specimen size on the fatigue crack growth rate was discussed. The fitting equation and the p-da/dN-ΔK curve of fatigue crack growth rate (with different confidence and reliability levels) were obtained by one-side tolerance factor analysis. In order to reasonably reflect the dispersion of material properties on the fatigue crack growth rate and fatigue crack propagation life, two novel statistical analysis methods were proposed, which can be used to describe the probability distribution of fatigue crack growth rate. Compared with the traditional statistical analysis method of probabilistic fatigue crack growth rate, the fitted curves from the novel statistical analysis methods yield more objective description on the probability distribution of crack growth rate.

Keywords

probabilistic fatigue crack growth rate / confidence / reliability / p-da/dN-ΔK curve fitting

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