航天器柔性多体系统动力学的高效建模方法

DYNAMIC MODEL OF FLEXIBLE MULTIBODY SYSTEM WITH TOPOLOGICAL TREE CONFIGURATION

以航天器为工程背景,提出了一种高效建模方法。文中采用有限元离散和模态叠加法描述部件的弹性变形。用铰链相对坐标建立了相邻柔性体之间的递推运动学方程。利用递推运动学方程、柔性体的牛顿—欧拉方程和铰链的约束特性,构造了单链多体系统动力学问题的递推算法。对树状多体系统的拓扑结构进行了研究,提出了研究树状多体系统动力学问题的求解过程控制方法,从而实现了树状多体系统与链式多体系统的统一,使得对单链多体系统建立的递推动力学方程能够直接用于求解树状多体系统的动力学问题。

This paper presents a computer-based mothed for the efficient formulation and solution of dynamic equations of flexible multibody system with topological tree configuration. Flexibiligy is modeled through the use of admissible functions from finite element analysis of component bodies. Recursive kinematic relations between contiguous bodies that are connected by articulated joints are defind by relative joint coordinates. These recursive kinematic equations are used with the Newton-Euler equations and the joint projection matrixes to develop a recursive algorithm for the dynamic analysis of a chain. A method called Sequence Control is presented for topological tree system. By using this method, the algorithm developed for the topological chain can be used for the dynamic analysis of arbitrary topological tree system.