基于三区间法的无人机发动机支架随机振动疲劳分析

Random Vibration Fatigue Analysis of UAV Engine Support Based on Steinberg Method

发动机支架是发动机和无人机连接的重要结构。发动机产生的随机振动是发动机支架工作过程中结构失效的主要原因,这种随机振动往往伴随发动机的振动疲劳损伤,进而造成无人机整体结构失效,使无人机的飞行安全面临重大隐患。基于三区间法对发动机支架进行随机振动分析,结合仿真结果对支架结构进行优化改进,对改进后的支架结构进行飞行试验,验证设计方法的可靠性。优化后的支架在试验过程中能有效分散随机振动造成的应力集中,且结构无疲劳损伤。该设计方法可以推广应用到各类使用活塞式发动机的无人机产品中,对减少由于随机振动造成的疲劳损伤具有较强工程意义。

The engine bracket is an important structure connecting UAV engine.Being the main reason for the structural failure of the engine bracket during the working process,the random vibration generated by the engine,is often accompanied by the vibration fatigue damage of the engine,which causes the failure of overall structure of the UAV and major hidden danger of drone flight saftety.So,the random vibration analysis of engine bracket is carried out based on Steinberg method,and its support structure is optimized and improved according to the simulation results.The flight test of the improved bracket structure is conducted to verify the reliability of the design method.The optimized bracket is effective in dispersing the stress concentration caused by random vibration without structure fatigue damage.The improved design method is applicable to all types of UAV products of piston engine,which has strong engineering significance to reducing the fatigue damage caused by random vibration.