Fatigue Life Prediction Method with Multi-Stress-Ratio Sparse Data

Rational characterization and quantification of un-certainty are key to fatigue life prediction. And multi-stress ratio sparse fatigue data introduce further effects of epistemic uncertainty to the quantitative characterization of uncertainty. Thus, in this paper, the survival a - s - <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$N$</tex> curves are firstly defined to express the uncertainty in the relationship of stress level and fatigue life, and the expression for the multi-stress-ratio condition is also clarified. Then the parameter estimation process are established suiting for uncertainty quantification with the sparse fatigue life data. Finally, a case study is used to show the effectiveness of the proposed model and method in the fatigue life prediction with multi-stress-ratio sparse data.