空间含镀层薄膜天线应力均匀化分析与验证

针对空间大尺度含镀层薄膜天线建模中尚未涉及镀层对应力均匀性影响的问题，以及双轴张拉试验装置施加拉力不均、薄膜平面度不足的问题，开展了空间含镀层薄膜天线应力均匀化研究。首先，进行了含镀层薄膜单元的力学建模，用经典层合板理论推导了含镀层薄膜区域的力学特性参数(杨氏模量和泊松比);其次，为了获得建模所必需的薄膜基底和镀层两个组分的力学特性参数，开展了均载薄膜双轴张拉试验，分别测得了镀层和薄膜的杨氏模量和泊松比；然后，在力学建模的基础上，分析了平面薄膜天线设计参数对应力均匀性的影响，得出了薄膜面积、厚度、边荷载、薄膜材料对应力均匀性的影响规律；以薄膜内应力标准差最小为优化目标，对空间大尺度含镀层薄膜天线进行了优化设计，使优化后的薄膜内应力标准差减小为优化前的4.6%;最后，对蠕变抑制效果进行了仿真校验，优化后的薄膜结构工作10年时蠕变导致的位移减小为优化前的27.6%,优化设计对空间大尺度薄膜的蠕变起到了有效的抑制作用。

Analysis and Verification of Stress Uniformity of Space Membrane Aperture with Coating

In order to solve the problem of the effect of coating on the stress uniformity is not involved in the modeling of space large scale coated film antenna, and the problems of uneven tension and low film flatness of the biaxial extension test set up, the stress uniformity of space membrane aperture with coating is studied. Firstly, the mechanical modeling of the coated thin film element is carried out, and the mechanical property parameters (Young’s modulus and Poisson’s ratio) of the coated thin film region are derived using the classical laminate plate theory. Secondly, in order to obtain the mechanical properties of the two components of the film substrate and the coating, the biaxial extension tests of the film are carried out, and the Young’s modulus and Poisson’s ratio of the film substrate and the coating are measured respectively. Then, the influence of membrane configuration, shell edge load and membrane material on stress uniformity are analyzed based on the mechanical modeling. Accordingly, a space membrane aperture is optimized to minimize the standard deviation of its stress. The stress uniformity is 4.6% after optimization. Finally, the effect on creep is verified and the simulation shows that the displacement caused by creep decreases to 27.6% of the displacement before optimization after 10 years of operation of the optimized film structure.The optimization is effective in restraining the creep of large scale space membrane aperture.