基于加权应变因子的叶片振动疲劳寿命预测  

Vibration fatigue life prediction of blades based on weighted-strain factors

作　　者：樊俊铃[1] 陈莉[1] 常文魁[1] 董登科[1] 郭杏林[2] 

机构地区：[1]中国飞机强度研究所,西安710065 [2]大连理工大学工业装备结构分析国家重点实验室,大连116024

出　　处：《应用力学学报》2016年第1期156-161,189,共6页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(11072045)

摘　　要：通过循环应力-应变方程和应变-寿命方程推导了可预测材料高、低周疲劳寿命的非线性疲劳损伤累积模型。模型中引入弹性、塑性加权应变因子对疲劳延性指数和疲劳强度指数进行修正,以考虑疲劳过程中弹塑性应变共同作用对疲劳损伤累积速率的影响。以某型航空发动机压气机叶片为研究对象,利用所建立的模型预测其疲劳寿命,并与试验结果、Basquin方程、改进的Basquin方程的预测结果进行对比分析。结果发现:在低应力水平(≤700MPa)下,三种预测模型给出的高周疲劳寿命误差小于30%;但是当应力水平达到770MPa时,所建立模型的预测精度比Basquin方程和改进的Basquin方程分别提高89.14%和22.73%。A nonlinear fatigue damage accumulation model for life predictions of low-cycle and high-cycle fatigue regimes is derived based on the cyclic stress-strain equation and the strain-life equation. The weighted elastic and plastic strain factors are introduced in the model to modify the fatigue strength exponent and the fatigue ductility exponent, so that the effects of the elastic and plastic strains on fatigue damage accumulation rate are taken into account. And then, the created model is applied to predict fatigue lives of the aero-engine compressor blades. Comparisons between the results of the present model and those of experiments, the Basquin equation and the modified Basquin equation are analyzed. The results show that the errors of predicted fatigue lives by the three models are less than 30% under lower stress levels(≤700MPa), but if the stress level is higher than 770 MPa, the predicted fatigue lives by the present model are, respectively, 89.14% and 22.73%, better than the results determined by the Basquin equation and the modified Basquin equation.

关 键 词：Basquin方程 加权应变因子 疲劳寿命预测 航空发动机 压气机叶片 

分 类 号：V215.5[航空宇航科学与技术—航空宇航推进理论与工程]