航空学报 > 2004, Vol. 25 Issue (3): 248-253

中心刚体-柔性悬臂梁系统的动力特性研究

蔡国平, 洪嘉振   

  1. 上海交通大学工程力学系 上海 200240
  • 收稿日期:2003-05-15 修回日期:2003-07-21 出版日期:2004-06-25 发布日期:2004-06-25

Dynamic Analysis of a Flexible Hub-beam System

CAI Guo-ping, HONG Jia-zhen   

  1. Department of Engineering Mechanics, Shanghai Jiaotong University, Shanghai 200240, China
  • Received:2003-05-15 Revised:2003-07-21 Online:2004-06-25 Published:2004-06-25

摘要: 对中心刚体-柔性悬臂梁系统的动力特性进行研究。首先采用Hamilton原理和有限元离散化方法,给出该系统的一次近似耦合模型以及相应的KED解耦模型,然后通过数值仿真对该系统的动力特性进行研究。研究中考虑了2种情况:中心刚体的转动惯量远大于柔性悬臂梁的转动惯量的情况和中心刚体的转动惯量接近柔性悬臂梁的转动惯量的情况。研究结果显示,传统的零次近似模型在处理大范围运动为未知的刚柔耦合动力学问题时同样存在失效的可能,而一次近似模型能够对系统的动力学行为进行正确的数学描述。当中心刚体的转动惯量远大于柔性悬臂梁的转动惯量时,一次近似模型的结果与零次近似模型的结果之间存在较小偏差;但当中心刚体的转动惯量接近柔性悬臂梁的转动惯量时,零次近似模型将导致错误的结果。

关键词: 中心刚体, 柔性悬臂梁, 零次近似模型, 一次近似模型, KED解耦模型

Abstract: The dynamic analysis of flexible hub-beam system is investigated. Firstly, by the Hamilton theory and using the finite element method for discretization, the first-order approximation coupling model and the corresponding KED uncoupled model are presented, respectively. Then dynamic characteristics of the hub-beam system are studied through numerical simulations. Two cases are considered in this study: the rotary inertia of the hub is much larger than or is close to that of the flexible beam. Simulation results demonstrate that there possibly exists failure in using the traditional zeroth-order approximation model for rigid-flexible coupling dynamic system when large motion of the system is unknown, whereas the first-order approximation model is valid. When the rotary inertia of the hub is much larger than that of the beam, the result using the zeroth-order approximation model has small error in comparison with that using the first-order approximation model. But when the rotary inertia of the hub is close to that of the beam, the zeroth-order approximation model may lead to wrong result.

Key words: hub, flexible cantilever beam, zeroth-order approximation model, first-order approximation model, KED uncoupled model