复合材料无人机滑撬式起落架设计与优化

摘要

根据某型号小型无人机总体要求,建立无人机滑撬式起落架的有限元模型,机身部分采用等效质点简化处理,进行无人机着陆过程的动力学仿真,得到无人机着陆过程中速度衰减趋势、过载值等仿真结果.通过对弓形梁截面尺寸及铺层角度的优化,使无人机落地过程中的过载值达到安全范围,并利用Tsai-Wu失效准则对弓形梁进行强度校核.设计并得到使无人机具有最小过载值且起落架结构不发生失效的弓形梁结构.此外,尝试使用不同的纤维复合材料,进一步提高滑撬式起落架的抗振性能.结果表明,合理的弓形梁尺寸可以提高起落架的抗振性,且芳纶纤维制成的起落架结构相比于碳纤维拥有更好的抗振性能.该研究成果对无人机滑撬式起落架的设计和制造具有重要的指导意义.%This paper established finite element model of landing gear skids according to the approximate requirement of a certain Mini-UAV (unmanned aerial vehicle).The airframe was simplified as a mass point.Then,by conducting the dynamic simulation of UAV landing process,from which a series of simulation results such as the attenuated trend of UAV's velocity,the acceleration of UAV could be calculated.For the sake of lowering the acceleration of UAV whthin a safety range,the sectional dimension of arched beams and filament winding angles were required to optimizate to meet the demands.Then,by using Tsai-Wu failure criterion to check the strength of arched beams,an appropriate arched beams structure and optimal filament winding angles were designed and obtained,which minimize the value of acceleration of UAV without structure failure.Besides,we attempte to use different kinds of fiber composites to further improve the vibration resistance of landing gear skids.Simulation results indicate that reasonable sectional dimension of arched beams could improve vibration resistance of landing gear skids.The optimal filament winding angles were (45o/-45o/90o/-90o/45o/-45°) which lowered Tsai-Wu failure indice.Meanwhile,the landing gear skids made of aramid fiber composites possessed greater vibration resistance than that made of by carbon fiber composites.The research results had a vital directive meanling on the design and manufacture of UAV landing gear skids.