关键词: 可靠性评定, 疲劳, 寿命预测, 随机本构关系, 应力分析

Abstract: A structural fatigue reliability analysis method is presented to consider random cyclic constitutions. A characterization for the random constitutions is established by using two probabilistic measurements of survival probability and confidence. The entire material constants in the constitutive equation are reasonably taken as dependent random variables. The probabilistic S-N relations covering from mid-short life regime to long life regime, representing structural fatigue strength, are also given on the two probabilistic measurements. Considering that the random constitutions derive random stresses of structures under cyclic loading and the probabilistic S-N relations introduce random strengths of structures anti-fatigued cycling, reliability assessment is then constructed by considering interference of the random cyclic stress and strength. The method can be applied to realize fatigue reliability life prediction and reliability assessment at arbitrary probability level. Availability of the present method has been indicated by the reliability life prediction and reliability assessment of RD2 type axle of Chinese railway freight cars.

Key words: Fatigue, Life prediction, Random constitutions, Reliability assessment, Stress analysis