发动机机匣低循环疲劳寿命的预测

本文介绍了一种基于局部应力应变法的发动机机匣低循环疲劳寿命预测方法。文中提出了确定机匣载荷谱的建议,论述了在多向应力状态下应如何确定等效应变,使在单向应力状态下确定的应变幅-疲劳寿命曲线可适用于多向应力状态。根据飞行的特点,提出了确定发动机机匣可靠性寿命的计算方法,最后通过实例,证明了所介绍的方法具有较好的精度。本方法比较简便,是一种很有前途的预测法。

Prediction of Low Cycle Fatigue Life of Engine Casing

Based on the local stress-strain approach, a LCFL prediction method of engine casing is introduced in this paper. A suggestion of determining the casing loading spectra is offered, and a method of determining equivalent strain in a multiaxial stress state is stated.Thus the strain amplitude-fatigue life curve determined under uniaxial stress state can be applied to multiaxial stress state. Based on the features of flight, the calculation method of determining reliablity life of the engine casing is also suggested. Finally,a typical example prores that the method presented in this paper is simple and convenient in application with higher precision.