论文部分内容阅读
针对某无人机前起落架在落震试验中地面载荷上升阶段出现的异常波动现象,通过对落震试验结果中缓冲器压缩状态和地面载荷关系的分析,判断该现象是由于缓冲器主油孔较小,主油腔中的气泡不能顺利转移到空气腔导致。建立了包含缓冲器主油腔气穴效应的起落架落震动力学模型,采用数值分析方法求解了该模型的动力学特性,计算结果与试验结果符合较好。通过震荡方法排除缓冲器主油腔中气穴后,落震试验得出的试验结果和不包含气穴效应的模型计算结果符合。落震试验对比表明:缓冲器轴向载荷波动现象由气穴效应引起;通过消除气穴方法后,起落架地面垂向载荷峰值下降0.3kN,起落架系统缓冲效率提高2%。
Aiming at the abnormal fluctuation phenomenon of the front landing gear in the fall test of ground load of a UAV, the paper analyzes the relationship between the shock absorber compression state and the ground load in the drop test result, Small holes, the main oil chamber bubble can not be successfully transferred to the air chamber caused. The droplet dynamics model of the landing gear, which contains the cavitation effect of the main oil chamber, is established. The dynamic characteristics of the model are solved by numerical analysis. The calculated results are in good agreement with the experimental results. After exclusion of cavitation in the main oil chamber of shock absorber by shock method, the experimental results obtained by the shock test are consistent with those of the model without cavitation effect. The comparison of the drop test shows that the shock load of the shock absorber is caused by the cavitation effect. After eliminating the cavitation method, the peak vertical load of the landing gear decreases by 0.3 kN and the cushioning efficiency of the landing gear system increases by 2%.