考虑间隙运动副的桁架单胞等效建模与分析

本文主要研究了含间隙运动副桁架单胞的等效建模方法.主要考虑了桁架单胞的等效刚度问题以及阻尼问题.首先从间隙铰链开始研究,提出全面的铰链模型;其次提出用位移法将桁架单胞等效成板,即把桁架单胞看成是由梁元组成的钢架结构,运用平面钢架位移法得出桁架单胞的等效刚度矩阵,进而得出结构的整体固有频率和等效后的板的刚度矩阵.最后用有限元软件ANSYS对单胞结构在不同边界条件下进行了模态分析,将在自由边界条件下的固有频率和解析得出的频率做了对比,发现二者有很好的吻合度.结果表明由于间隙运动副的存在,使得桁架单胞结构的刚度降低,柔性增强.

Equivalent modeling and analysis of truss antenna unit cell with clearance joints

This paper studies the equivalent modeling method of truss cell elements with clearance joints. The equivalent stillness and damping problem of unit cell truss are mainly considered. Firstly, a comprehensive hinge gap model is constructed by considering on the gap hinge. An equivalent method is then put forward to simplify the truss unit cell to a plate-like structure. As structural element is assumed as a steel beam, the displacement method is used to get the equivalent stillness matrix of plane truss unit cell in different boundary condition. The overall natural frequency and plate equivalent stiffness matrix after equivalence are then obtained. Finally, finite element analysis (FEM) by a software of ANSYS is proposed for structural modal analysis of the structure with clearance joint. The results show that when the stiffness of the truss structure unit cell is reduced, the flexibility is increased. © 2018 Journal of Dynamics and Control. All rights reserved.