关键词: 低周疲劳;异方差回归;概率寿命;局部应变-寿命法

Abstract: To study the chief factors that affect the precison of disk LCF life estimation models, and improve evaluate precision of the models, the material parameters of three strain-life estimation models were obtained by heteroscedastic regression analysis method, and the fatigue life distribution of a aeroengine fan disk was simulated. The probabilistic life of the disk was finally obtained. Compaired with the experimental data, LCF life estimated by the heteroscedastic regression method is better than one by the homoscedastic regression method. The LCF life predicted by the equivalent strain model is much higher than the experimental value,while the results of the first principal strain model fit well. The estimated value of the maximum shear srain model is between the estimated value of other two models. If average extending stress was replaced by peak extending stress for the maximum shear srain model, the predicted probabilistic fatigue life agrees well with the experimental data. 

Key words: Low cyc fatigue; Heteroscedastic regression; Probabilistic life; Local strain-life method