星载抛物面天线热变形敏感性分析

热变形是影响星载天线精度的主要因素,分析影响星载天线在轨热变形因素的敏感性是控制其变形的基础.基于经典薄壳变形理论,采用一种曲线坐标系下的样条壳体单元,研究了不同太阳辐射角度下抛物面天线热变形均方根(RMS)对正交各向热传导系数的敏感性.为确定计算参数对抛物面天线在运行中变形RMS的影响,以运行一周中最大RMS(MRMS)为目标,基于正交试验方法分析了正交各向热传导系数、热膨胀系数、弹性模量和比热容对MRMS的敏感性.结果表明,在其所取水平条件下,热膨胀系数影响最大,热传导系数次之,弹性模量的影响较小,比热容最小.优化获得的参数为星载抛物面天线的复合材料铺层设计提供参考.

Sensitivity analysis of thermal deformation of parabolic antenna in orbit

Thermal deformation is a main factor affecting antenna performance. Sensitivity analysis of thermal deformation of parabolic antenna in orbit is the base of controlling deformation. A spline function shell element in orthogonal curvilinear coordinate system based on classic shell theory was used for antenna thermal analysis. For a parabolic antenna, thermal conductivity sensitivity of root mean square of displacements(RMSD) of reflector shell was analyzed under three steady-states, result shows that the sensitivity is dependent on load cases, so the maximum of RMSD(MRMS) during an orbit period is treated as design object. Orthogonal simulation experiment method was used for sensitivity of thermal conductivity in shell plane and in transverse direction, specific heat, modulus of elasticity and thermal expansion coefficient to MRMS. The results show that in the levels thermal expansion coefficient has most, thermal conductivity has more, modulus of elasticity has less and specific heat has least influence on MRMS. The optimum parameters achieved can provide reference for ply optimization design of parabolic antenna in order to control the deformation．