燃气轮机涡轮盘-片多轴低周疲劳寿命研究

Research of Fatigue Life Prediction of Multiaxial Low-cycle for A Gas Turbine Disc and Blade

针对燃气涡轮转子盘-片,考虑多轴应力对其疲劳寿命的影响。引入三种基于临界面法的多轴疲劳寿命预测模型,将临界面定义为最大破坏平面,并给出了寿命预测模型的执行步骤。结合转子盘-片实例进行了应用研究,结果显示:基于临界面法的多轴疲劳寿命预测结果具有较高的精度,其中Fatemi-Socie(FS)改进模型得到的结果与转子盘-片的实际疲劳寿命基本一致,并且模型中引入有限元计算是可行的,可以减少做一些复杂的实验。因此,研究结果具有一定的实际工程意义。

Aiming at the forth blade-disc of a certain gas turbine,the multiaxial stresses effect is considered in the life prediction analyzing.Three variants of critical plane models are introduced,identifying the critical plane as the plane associated with the maximum damage and a computer-based procedure for multiaxial fatigue life assessment incorporating critical plane multiaxial damage models is presented.Also actual engineering instance was done with these models.The computational results show that multiaxial fatigue life prediction based on critical plane models has an upper precision.Especially,the amendatory Fatemi-Socie（FS） model for fatigue life prediction well consistent with the result of real blade-disc fatigue life,and the FEM which is applied in this paper is useful.Consequently,the results satisfy the applications of practical engineering.