涡轮盘的三种低周循环疲劳寿命预测方法对比研究

为了确定涡轮盘的低周循环疲劳寿命,在前人研究的基础上对基于局部应力应变法的低周循环疲劳寿命计算程序的计算结果进行了验证,并将其应用于某涡轮盘的寿命评估中.分别对比分析了Morrow平均应力方程、修正的Morrow以及SWT参数模型三种方法下,输入名义主应力谱、名义等效应力谱与真实主应力应变谱的寿命计算结果.研究表明:3...

Comparative Study on Three Prediction Methods for Low Cycle Fatigue Life of Turbine Disk

In order to determine the low cycle fatigue life of the turbine disk,based on the previous studies,the calculation results of the low cycle fatigue life calculation program based on the local stress and strain method were verified and applied to a turbine disk life assessment.The life calculation results of the three models of Morrow mean stress equation,modified Morrow and SWT parameters and input nominal principal stress spectrum,nominal equivalent stress spectrum and real principal stress strain spectrum were compared and analyzed,respectively.The research results show that,for this example,among the three models,the SWT equation model predicts the shortest life,followed by MORROW,and then the modified.Compared with the modified MORROW,the difference in the SWT and MORROW calculation results is relatively small,with the error within 50%.The real principal stress strain spectrum and the nominal principal stress spectrum have the same trend of life prediction.Finally,the SWT model based on the nominal principal stress spectrum is selected for life prediction.With the life safety factor at 5,the life of the vent hole of the disk is 1941 cycles,the life of the flange hole is 24 164 cycles,and the life of the disk center is 16 235 cycles.