基于谱分析的30m望远镜三镜支撑结构地震分析

为了满足30 m望远镜 （TMT）三镜系统（M3S）对抗震性能的要求，对在返回周期为200年和1000年的地震载荷条件下的三镜支撑结构的性能进行了分析。首先，根据三镜支撑结构的特点，对TMT整体的地震响应谱进行了修正，得到了适用于三镜支撑结构的地震响应谱。然后，分析了三镜支撑结构在不同等级地震激励下的位移、应力和加速度响应。分析结果显示，当返回周期为1000年的地震从水平面内两个正交方向及竖直方向同时传递到三镜支撑结构中时，系统响应最大；此时，三镜支撑结构中各部件的最大加速度为2.844g，最大位移为1.544 mm，最大应力为552.316 MPa，三镜上最大应力为1.401 MPa。根据材料力学性能可知，侧支撑杆会发生破坏，需要采取地震防护措施对三镜进行保护。本文在进行谱分析时较完整地考虑了各项因素，结果数据精确可靠，可为三镜系统的详细设计提供指导。

Seismic analysis of TMT M3 cell assembly based on spectral response

In order to satisfy the anti-seismic requirement of Tertiary Mirror System(M3S)in a Thirty Meter Telescope (TMT), the structural responses of Tertiary Mirror Cell Assembly (M3CA) under the earthquakes with 200-year and 1000-year return periods were analyzed. Firstly, a seismic response spectrum of M3S was established by modifying the seismic response spectra of TMT according to M3S mechanical character. Then, the structure responses of displacement, stress and acceleration under different level earthquakes were analyzed. The analysis results show that the peak response appeares when the earthquake with 1000-year return periods transmits to M3S in three directions (two horizontal orthogonal and a vertical). The peak acceleration of M3CA, maximum displacement and the peak stress are 2.844g, 1.544 mm, and 552.316 MPa,respectively, moreover, the peak stress on Tertiary Mirror (M3) is 1.401 MPa. The investigation of material property indicates that the lateral support rods will be broken at this moment and the protective support for M3 is recommended. As a result of sufficient consideration of different influencing factors in spectrum analysis, the data can provide reliable references for detail designs of M3Ss.