1.5m口径垂直状态短筒长焦距平行光管次镜支撑系统设计

非球面次镜相对于主镜的位置和稳定性对光管的检测和校验性能起着非常重要的作用。从原理上分析了次镜支撑系统，同时建立改进的支撑桁架动力学模型；然后，使用降维处理的方法通过有限元分析对结构进行优化设计；最后，分析温度变化对1.5 m光管性能的影响。结果表明，采用的切向三翼支撑结构，减小了系统的遮拦比而且保证了结构的刚度，改进桁架的比刚度得到改善，从而使整个支撑系统的一阶谐振达到62 Hz；改变局部结构材料降低了温度变化对光学系统的影响，使波像差由/20减小为/30。提出的设计方案精度高，稳定性好，可以满足设计要求。

Design of SM support system of 1.5 m aperture vertical collimator with long focus and short tube

The relative position and stability between primary mirror and aspherical secondary mirror(SM for short) is important to test and checkout for the collimator. First, the supporting system of secondary mirror was analyzed according to the theory, and the dynamics model of supporting trusses was built. Then, the secondary supporting system was designed, optimized according to the disposal of decreasing dimension by FEA. Finally, effects caused by temperature were analyzed. The results show that tangential spider van support could reduce the masking and keep the stiffness at the same time. The ratio of rigidity of the improved supporting truss is uprated, which make the 1st resonance of the whole system arrive at 62 Hz. The effect of temperature also can be decreased by change material of local structures, making the wavefront error of system change from /20 to /30. The scheme has fine accuracy, well stability and meet the design requirement.