大型空间结构热?动力学耦合分析方法综述

近年来, 各种大型空间结构逐渐在我国航天工程中得到应用, 相应的热诱发振动问题也日益受到重视. 在此背景下, 有必要进一步梳理热诱发振动的机理和分析设计中的关键问题. 本文将结合作者的研究工作对此问题进行全面介绍, 并主要强调在分析复杂工程结构的热诱发振动问题时需要注意的特殊问题. 本文首先介绍了可以高效地分析空间薄壁杆件结构(包含开口和闭口薄壁杆件)在辐射换热条件下的瞬态温度场的Fourier有限元方法; 随后介绍了热诱发振动的线性和非线性分析方法, 强调了热?动力学耦合效应. 为了对复杂空间结构产生热诱发振动的必要条件给出解析表达式, 本文将瞬态温度场与振动位移场统一在模态空间中进行分析, 从而得到评价热诱发振动剧烈程度的一般性条件. 在此基础上, 本文进一步讨论了热诱发振动的运动稳定性问题, 以悬臂杆件的热颤振准则为例揭示了热诱发振动发散的物理机理, 并给出了评定复杂工程结构热颤振的分析方法. 论文最后概要地指出了在热诱发振动的地面试验和抑制方法中需要注意的问题, 并对将来的研究工作进行了展望. 

REVIEW OF THERMAL-DYNAMICAL ANALYSIS METHODS FOR LARGE SPACE STRUCTURES

In recent years, various large space structures are gradually implemented in the aerospace industry of China. Thus, the corresponding thermally induced vibration problems are drawn more and more attentions. Under this background, it is necessary to clarify the underling mechanism of the thermally induced vibration phenomenon and the corresponding critical issues in the analysis and design. Based on the research work of the authors, this article gives a comprehensive review of the related problems and mainly focuses on some special aspects in the thermally induced vibration analysis of complex engineering structures, which are compose of many thin-walled bars. Firstly, this article introduces a Fourier finite element that decomposes the temperature into the average part and the perturbation part. In this way, the thermal conduction equation under thermal radiation can be decoupled into the corresponding two parts due to the orthogonal property of the Fourier series. Thus, the transient temperature field of closed-section or open-section thin-walled bars can be efficiently analyzed. Based on this kind of element, both linear and nonlinear methods for the thermally induced vibration analysis are presented with the emphasis on the thermal-dynamic coupling effect. In order to give the analytical form of the necessary condition of the thermally induced vibration, this paper analyzes the properties of the transient temperature and the oscillation displacement in the mode space, and thus it obtains a general criterion to evaluate the intensity of the thermally induced vibration. Based on these work, the dynamic stability of the thermally induced vibration is further discussed by not only the mechanism reflected in the thermal flutter criterion of a cantilever bar, but also the thermal flutter analysis of complex engineering structures. Finally, the conclusion part briefly addresses some important factors in the underground testing and the method of suppressing the thermally induced responses. Some research topics need further investigating in the future are also envisaged.