粉末冶金涡轮盘简单模拟件低周疲劳寿命研究

采用光滑圆棒试样和带孔平板试样,对不同温度下的镍基粉末高温合金(FGH95)的低周疲劳(LCF)寿命进行了试验研究和有限元分析。在详细分析试验和有限元计算结果的基础上,提出了复杂应力状态下的低周疲劳寿命模型。模型寿命表达为真实应力幅的函数,模型参数由不同应力水平加载作用下的光滑圆棒试样试验结果给定,进一步采用涡轮盘简单模拟件即带孔平板试样对比验证LCF寿命模型的有效性。有限元计算结果显示,理论预测寿命与试验结果能很好地吻合。

A Low-Cycle Fatigue Life Model for Simplified Turbine Disk Simulation Specimens of Powder Metallurgy Superalloys

The low-cycle fatigue(LCF) behavior for specimens of powder metallurgy superalloys(FGH95) of smooth round rod and plate with holes was studied by experiment and finite element method under different temperatures.Based on experimental data and finite element analysis results,a low-cycle fatigue life model is proposed for the powder metallurgy superalloys under multiaxial stress states.The LCF life is a power function of true stress amplitude corresponding to the maximum and minimum loadings.The LCF model parameters can be obtained from the experimental data of smooth round specimens under different stress levels.Further,a plate specimen with holes was studied to validate the LCF life model.Good agreement is obtained between the finite element analysis and experimental results.