推力作用下细长弹箭横向振动及稳定性分析  

TRANSVERSE VIBRATION AND DYNAMIC STABILITY ANALYSIS OF SLENDER PROJECTS UNDER THRUST

作　　者：许赟[1] 谢长川[1] 杨超[1] 

机构地区：[1]北京航空航天大学航空科学与工程学院,北京100083

出　　处：《工程力学》2009年第12期211-215,221,共6页Engineering Mechanics

基　　金：国家自然科学基金项目(90716006;10432040);新世纪优秀人才支持计划项目(NCET-04-0170)

摘　　要：该文分析了细长弹箭类飞行器在推力作用下的动力学稳定性和横向振动的频率与振型特性。将弹箭飞行器简化为非均匀的梁模型,推力定义为随动力,根据非保守系统的Hamilton原理,建立了随动推力作用下的非均匀梁振动分析数学模型,有限元方法用于分析模型的数值计算,得到了均匀梁模型和典型弹箭飞行器模型的结构振动特性和动力学稳定性随推力变化的情况。结果表明:随动推力会诱发弹箭飞行器的动力学失稳;推力同时影响结构的横向振动的频率和振型特性,在推力作用下模态振型的波谷沿模型发生移动,振型的幅值亦会发生改变。The paper discusses dynamic stability and frequency/mode characteristics of lateral vibration of slender projects under a thrust force. The slender project is idealized as a non-uniform beam, with the end rocket thrust defined as a follower force. Then the mathematic model for the vibration of a non-uniform beam with a follower force is built based on the extended Hamilton＇s principle for a non-conservative system. Finite element method is introduced in the simulation of the model; then the stability analyses of a uniform beam model and a simplified model of generic slender projects are carried out to obtain the vibration characteristics and dynamic stability of the two models, meanwhile, whose variation with the thrust force is analyzed. The results show that the follower thrust may cause the dynamic instability of slender projects; the thrust affects transverse vibration modes and frequencies; the thrust causes the moving of the trough along the body of the project, as well as the changing of mode amplitude.

关 键 词：结构动力学 动力学稳定性 随动推力 振动 弹箭飞行器 

分 类 号：V214.34[航空宇航科学与技术—航空宇航推进理论与工程]