Probabilistic Modeling of Damage Accumulation for Fatigue Reliability Analysis

For high-speed trains, reliability prediction of railway axles plays an important role in preventing accidents due to fatigue. Using a nonlinear damage accumulation concept, a probabilistic S-N curve and one-to-one probability density function transformation, a probabilistic approach for modeling damage accumulation is developed to analyze the fatigue reliability of railway axle steels. Through characterizing the damage accumulation process as a distribution of degradation path, the proposed method captures a nonlinear damage accumulation phenomenon under variable amplitude loadings. The fatigue reliability is then analyzed and demonstrated through probabilistic modeling of cumulative damage, and an agreement between the predicted results and the experimental measurements under different loading conditions is obtained.