飞机作动器耳片疲劳断裂失效分析

Fatigue Failure Analysis of Aircraft Actuator Lugs

针对某型作动器在耐久性试验中出现耳片断裂的问题,将耳片受载分为静态冲击和动态冲击两种不同情况考虑,对耳片在作动器不同工作状态下的冲击载荷进行计算分析,并基于细节疲劳额定值(DFR)方法对耳片进行了疲劳寿命计算。分析结果表明,动态冲击载荷较静态载荷大、载荷循环多,导致耳片应力水平偏高、损伤偏大是耳片过早断裂的主要原因。针对断裂原因,提出增大耳片厚度的改进措施,并分析了改进措施的有效性。类似的作动器耳片设计中,应考虑动态冲击载荷对结构疲劳寿命的影响。

Aiming at the fatigue failure of actuator lug during the fatigue test, static load and dynamic impact load of the lugs under different working conditions are calculated respectively, and fatigue life of the lugs is calculated based on Detail Fatigue Rating(DFR) method. The results indicate that larger load and more load cycles generated by dynamic impact compared with static analysis resulted in higher stress level and bigger damage on lugs, which was the cause of lug failure. Based on analysis result, improving the thickness of the lug is recommended and the effect of thickened lug is proved by analysis. The effect of dynamic impact load on the fatigue life of the structure should be considered in the similar actuator lug design.