望远镜风载分析研究

Research on Wind Load Analysis of Telescope

  • 摘要: 望远镜工作时受风载荷影响不可避免,风载荷会造成主次镜面间产生相对位移,进而产生望远镜指向误差,降低望远镜工作性能。该文基于实际激光通信望远镜建立望远镜有限元模型,分别对望远镜进行了静态和随机风载分析。首先,在静风载分析中得出系统所受静风载变形量;然后对望远镜进行模态分析,得出系统动态特性;再对系统进行谐响应分析,判断系统光轴扰动特性;最后,对望远镜系统进行PSD分析,得到随机风载作用下主镜、副镜位置随机变化的统计结果。计算结果得出:风载引起的次镜相对于主镜在Y向的偏移量为1.6 μm,Y向风载引起的光轴指向误差RMS值为0.55″,在精度允许范围内。所得结论为类似望远镜风载研究提供了参考。

     

    Abstract: The operation of a telescope is inevitably affected by wind loads, which can cause relative displacement between the primary and secondary mirrors, resulting in telescope pointing errors and reduced telescope performance. This article is based on an actual laser communication telescope, establishes a finite element model of the telescope, and conducts static and random wind load analysis on the telescope. Firstly, in the static wind load analysis, the deformation amount of the system under static wind load is obtained; then, modal analysis is performed on the telescope to obtain the dynamic characteristics of the system, and the harmonic response analysis is conducted on the system to determine the optical axis disturbance characteristics of the system; finally, the PSD analysis is performed on the telescope system to obtain statistical results of the random changes in the positions of the primary and secondary mirrors under random wind loads. The calculation result shows that offset of the secondary mirror relative to the primary mirror in the Y direction caused by wind load is 1.6 μm; the RMS value of the optical axis pointing error caused by Y-direction wind load is 0.55 inches, which is within the allowable accuracy range.

     

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