某型飞机在使用过程中,多次发生配重组件破损,滚柱飞出而击伤发动机,严重威胁飞行安全.为分析配重组件破损的原因,基于配重的工作原理,分析了发动机油门快速操纵对曲轴扭转振动的影响,依据扭纵耦合理论,对滚柱冲击挡片的机理进行了研究,并完成了试验验证.建立了配重组件在冲击载荷作用下的有限元计算模型,并对配重组件进行了机械性能测试,采用疲劳强度安全系数法,完成了配重组件的强度分析.研究结果表明,发动机油门的快速操纵引起配重摆动角度过大,配重为非线性摆动,其摆动频率与曲转扭转振动频率差异过大,配重消除曲轴扭转振动效果差,曲轴产生剧烈的扭转共振,扭转振动耦合成轴向振动,造成滚柱高频冲击挡片.在冲击载荷作用下,挡片的疲劳强度最小,最易发生疲劳破损,可适当改善其疲劳强度,提高配重组件不发生疲劳破损的可靠性.%In a certain airplane working process, it often happened that counterweight-components fractured, the roller flied out and damaged engine, which was a serious threat to flight safety. In order to analyze the cause of counterweight-components fracture, the impact of rapid manipulation of engine throttle on crankshaft torsional vibration was analyzed base on working principle of counterweight. The mechanism of roller impact washer was studied based on coupled torsional-axial vibration theory and the experiment verification has been completed. The finite element calculation model of counterweight-components with impact load was established, the mechanical properties of counterweight-components was tested, and the strength analysis of counterweight-components has been completed based on safety factor method of fatigue strength. Research results show that the rapid manipulation of engine throttle causes excessive swing-angle of counterweight, which works in nonlinear swing. The counterweight swing frequency and the crankshaft torsional vibration frequency are greatly different, so the effect of the counterweight eliminating crankshaft torsional vibration is poor. The crankshaft generates strong torsional vibration, and this vibration is coupled as crankshaft axial vibration, causing the roller generate high frequency shock to washer. Under impact load, the fatigue strength of washer is the smallest in counterweight-components, fatigue fracture easily happens in washer. Appropriate improve of washer fatigue strength is in favor of avoiding fatigue fracture and improving reliability of counterweight-components.
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