新型无杆飞机牵引车夹持举升机构静刚度分析

Stiffness Analysis for Holding and Lifting Mechanism of a Novel Towbarless Aircraft Tractor

研究一种新型无杆飞机牵引车夹持举升机构的静刚度建模方法。对机构的夹持举升动作进行分解,重点研究后挡板闭合后提升机轮的过程。在完成对该机构位置逆解分析的基础上,分析连接承载斗的各杆件受力及变形情况。利用虚拟机构法,根据速度映射关系,求出杆件变形引起承载斗的位姿变化,再利用小变形叠加原理,求出机构的整体变形。根据外载荷与机构整体变形之间的关系,求出机构的静刚度矩阵。通过算例确定机构的静刚度在工作空间的分布规律,并利用ANSYS软件验证了该建模方法的正确性。

An analytical approach for the stiffness modeling of a novel towbarless aircraft tractor＇s holding and lifting mechanism was presented. The movement of the holding and lifting mechanism was decomposed and particular interest was placed on the process that lifting the airplane＇s nosewheel after the backboards were closed. On the basis of the inverse position analyses,the compound limbs of the mechanism were analyzed by the static analysis and the corresponding deformations were calculated. The pose deformations of the carrying bucket caused by compound limbs were obtained by using the virtual mechanism method and according to the velocity mapping relationship between inputs and outputs. The total deformations of the mechanism were derived through the superposition principle at small strain. According to the relationships between the external load and the total deformation of the mechanism,the total static stiff-ness model of the mechanism was formulated. The stiffness distributes throughout the task workspace were evaluated and the model of the mechanism was validated by a commercial ANSYS software.