米级口径跟踪架的设计与模态分析

摘要

The larger the telescope aperture, the structural rigidity of the requirements for tracking aircraft higher, for photo-electric theodolite. Photo-electric theodolite’s aperture is designed related to tracking frame, so tracking frame is more and more attention. In this paper, U-type track frame horizon as an example, the two key components are designed with square steel tube truss structure. By finite element design and modal analysis, solving the inherent resonant frequency. In the last, we used to design in steel casting and welding methods. This paper discusses a new design of welded steel pipes. And it has a modal analysis. So that it has a greater carrying capacity and higher stiffness and lighter, more abundant reserves of torque. The mechanical resonance frequency is 78 Hz for tracking frame after a vibration test and sweep test.%在光电经纬仪中，望远镜的口径越大，对跟踪架的结构刚度要求越高。因此对于跟踪架的结构设计备受关注。本文以地平式U型跟踪架为例，对其中的两个关键部件如四通和转台采用方钢管桁架结构进行设计，结合有限元设计及模态分析，求解其固有的谐振频率。通过与传统的钢板焊接结构比较，结果表明方钢管桁架结构刚度更高，重量更轻。对于口径达到1 m的地平式经纬仪跟踪架，重量达到6200 kg时，经过激振试验和扫频测试，测得机械谐振频率达到了78 Hz。