大型柔性空间结构热-动力学耦合系统的非线性有限元分析  

The Thermal-Dynamic Coupling Analysis of Large Flexible Space Structures by Finite Element Method considering Geometric Nonlinearity

作　　者：范立佳[1] 段进[2] 向志海[1] 薛明德[1] 岑章志[1] 

机构地区：[1]清华大学工程力学系,北京100084 [2]中国建筑科学研究院,北京100013

出　　处：《宇航学报》2009年第1期299-304,共6页Journal of Astronautics

摘　　要：针对在轨航天器柔性附件的热-动力学耦合系统,发展了一种基于更新Lagrange格式的非线性有限元分析方法。构造了一种一维温度杆单元,该单元通过增加节点自由度数能够同时得到薄壁杆件横截面的平均温度和沿杆截面周向的温差,这些温度直接产生相应的热轴力、热弯矩和热双力矩。利用Rodrigues公式得到薄壁梁在大转动情况下的坐标转换矩阵,并推导了非线性动力学方程。进一步考虑结构变形和热流入射角的相互影响后,就得到了高度非线性的热-动力学耦合有限元方程。首先用标准考题验证了该方法的正确性,然后利用该方法对哈勃太空望远镜太阳翼的热诱发弯扭耦合振动问题进行了分析,给出了可能导致其失效的模式。In this paper, a geometric nonlinear Finite Element （FE） method was developed to analyze the thermal-dynamic coupling systems of large flexible space structures based on the updated Lagrange formula. A kind of I-D temperature element of thin-walled beam was presented by adding additional degrees of freedom at each temperature node. The average temperature and temperature gradient of the cross section could be given at the same time, consequently, the thermal axial force, the thermal moments and bi-moments could be calculated. On the basis of the above temperature element, an updated Lagrange FE scheme had been formulated for the nonlinear thermal-dynamic problem, where the sectional warping and the large rotation were taken into account. The interaction between the structural deformation and the absorbed heat flux can be formulated and the thermal-structural coupling effect is thus considered. Numerical examples demonstrate the validity of the presented method. Using this method, the thermally-induced bending-torsion vibration of the solar array on Hubble Space Telescope was obtained. The results are consistent with actual observations.

关 键 词：薄壁杆件 热-动力学耦合 非线性 瞬态温度场 有限元法 

分 类 号：V414.1[航空宇航科学与技术—航空宇航推进理论与工程]