航天器大型太阳翼的热-结构耦合动力学建模与非线性振动研究

Modern spacecraft usually have large-span solar panels to provide sufficient power to achieve stronger function and longer life. A typical large-span solar panel is joint-connected multi-plate structure, and contains significant geometric nonlinearity and joints nonlinearity. Subjected to the time-varying thermal loading in space, complicated even unstable nonlinear vibration will be excited for this kind of solar panels, which brings great risks for the safe and stable in-orbit operation of spacecraft. Starting from this dynamic problem in aerospace engineering, the thermal-structural coupling dynamic modeling and nonlinear vibration analysis for large-span solar panels are studied based on nonlinear dynamic theory. The main contents can be stated as follows: to develop a novel approach to construct the low-dimensional thermal-structural coupling dynamic model for the joint-connected multi-plate solar panel; to investigate the behaviors of thermally induced nonlinear vibration and analyze its stability for large-span solar panels; to study the nonlinear characteristics of thermally induced rigid-flexible coupling vibration of spacecraft with large-span solar panels. The research achievements will reveal the influences of system parameters and nonlinear factors on the thermally induced nonlinear vibration and its stability, and provide theoretical supports for the large-span solar panels’ optimization design as well as the modern spacecraft's safe and stable in-orbit operation. Moreover, the present work may show us a viable path to construct low-dimensional dynamic model and perform theoretical study on thermal-structural coupling for multi-plate structures.

新一代航天器通常安装大型太阳翼，以满足功能强和寿命长的能源需求。典型的大型太阳翼由多块太阳能板通过铰链连接而成，含有显著的几何非线性和铰链非线性。在空间时变热载荷作用下，此类太阳翼将产生复杂的非线性振动，甚至失稳，这对航天器的在轨安全稳定运行带来了极大的隐患。对此，本项目从这一工程实际中的动力学问题出发，基于非线性动力学理论，开展航天器大型太阳翼的热-结构耦合动力学建模与非线性振动研究，主要内容包括：多板组合太阳翼的低维热-结构耦合非线性动力学建模，大型太阳翼部件的热诱发非线性振动与稳定性分析，太阳翼热振与航天器姿态的刚柔耦合非线性动力学特性研究。项目研究结果将揭示系统参数和非线性因素对大型太阳翼热诱发非线性振动和稳定性的影响规律，为新一代柔性航天器的太阳翼结构优化设计和在轨安全稳定运行提供理论支撑和应用参考，并为多板结构的低维建模和热-结构耦合理论研究提供思路。

本项目从在轨运行航天器的大型太阳翼所面临的瞬态热-结构耦合动力学问题出发，开展了热-结构耦合动力学建模与非线性振动特性分析的相关研究。主要内容和结果包括：1）多板组合太阳翼全局模态求解及低维非线性动力学模型构建。发展了多板组合结构的全局模态求解方法，基于此建立了多板组合太阳翼的低维高精度非线性动力学模型。2）多板组合太阳翼热-结构耦合非线性振动与稳定性分析。研究发现，在突加热流工况下，随着热流入射角度增大，系统热振响应由收敛逐渐变为发散；稳态热环境下，太阳翼临界屈曲温度与热模态频率随基板长宽比、蜂窝胞元尺寸增大而降低，随板间铰链刚度增大而增大。3）安装大型太阳翼的航天器动力学与控制研究。针对航天器捕获外部载荷的动力学行为进行分析，发现外部载荷撞击角度与速度主要影响航天器姿态及太阳翼振动，撞击速度越高，太阳翼振幅越大；设计了协同控制策略，实现了空间热环境下航天器姿态运动与太阳翼结构振动的有效控制。4）非线性系统动力学特性及稳定性分析。发展了非线性系统周期解自动追踪方法，可自动判断解轨线分岔、转向、稳定性，为后续开展稳态热环境下受周期扰动激励的航天器的复杂非线性振动特性分析提供了有效手段。本项目研究成果可为大型多板组合太阳翼的设计或分析提供理论依据。