基于有限元柔性体理论的起落架落震仿真分析

Analysis and Simulation of Landing Gear’s Falling VibrationBased on Finite Element Flexible Body Theory

以某飞机起落架为研究对象,研究落震动力学问题。根据前起落架的结构特性,利用多体动力学建模技术,建立前起落架多柔性体动力学(MFBD)模型,并进行落震仿真分析及非线性接触研究。采用落震试验数据对模型进行校验,仿真结果与试验数据较为吻合。通过分析缓冲器零件的变形,考虑接触因素的多柔体动力学模型能更真实反应实际情况,以最大降落速度工况进行落震仿真,同时对起落架关键零件进行强度校核,以及缓冲器内部零件进行非线性接触计算,求得不同材质的下凸轮及底托受到的垂向力与摩擦力,获得在物理试验中难以测量的数据,分析结果对起落架设计具有重要意义。

The landing gear of a certain aircraft is used as the research object to study the dynamics of the earthquake.According to the structural characteristics of the front landing gear,the multi-body dynamics modeling technology is used to establish a multi-flexible body dynamics(MFBD)model of the front landing gear,and the simulation analysis of the landing gear and the nonlinear contact research are performed.The model was verified using the drop test data.The simulation results are in good agreement with the test data.By analyzing the deformation of the shock absorber parts,the multi-flexible body dynamic model considering the contact factors can more realistically reflect the actual situation,and perform the shock simulation at the maxi-mum landing speed.At the same time,the strength check of the key parts of the landing gear and the shock absorber The internal parts are subjected to non-linear contact calculation to obtain the vertical force and friction force of the lower cam and the bottom bracket of different materials.Data that are difficult to measure in physical tests are obtained.The analysis results are of great sig-nificance to the design of the landing gear.