大型空间结构热弹性非线性有限元分析

由薄壁管组成的大型空间结构在外层空间受到太阳等星体的辐射加热，其热变形是值得关注的。为了准确地预测这种变形，首先推导了一种梁的热弹性几何非线性增量有限元格式，用以分析该类结构的热-力学响应，然后考虑到空间结构热流输入与变形耦合的特性，提出了一种热-力学耦合分析的有限元方法。对哈勃太空望远镜太阳能帆板热变形的实例计算表明，数值解与理论解符合较好。数值算例表明，结构内部热变形的不一致程度越大，考虑几何非线性对于热变形计算结果的影响越大；热流入射方向角和热变形大小是影响耦合效应的主要因素。

Thermal-structural Finite Element Analysis of Large Space Structure Considering Geometric Non-Linearity

Large Space structures consisting of thin-walled tubes are subjected to the heat flux from the sun and other bodies. The thermal deformation of these structures is concerned. For predicting this deformation accurately, a geometric nonlinear finite element method is presented for beam element. Then a coupled thermo-structural finite element method is present considering the heat flux coupled with thermal deformation of space structure. Numerical result of thermal deformation of the solar array on the Hubble Space Telescope agrees well with the analytical solution. Numerical examples show that the effect of geometric non-linearity on the computation increases with the difference of thermal deformation of different components, and the thermo-structural coupled effect is mainly determined by the incident angle of heat flux and the magnitude of thermal deformation.