离轴多反射镜系统支撑结构的设计与装调

针对离轴多反射式空间相机设计了一种胶接桁架支撑结构。采用T700碳纤维复合材料制造桁架杆,钛合金材料制造杆接头,J133环氧树脂胶作为黏合剂,桁架杆两端的钛合金接头作为相机各组件的接口。给出了装调和胶接的辅助设备及相应的方法和步骤:即利用工装进行预装调,确定杆接头位置;然后通过抹胶完成正式装调,利用定位销钉实现杆接头复位;最后在室温下固化5~7天,拆除工装和销钉后桁架装调完毕。有限元分析和力学振动试验表明,固化完成的桁架一阶谐振频率优于90Hz,所支撑镜头的一阶谐振频率优于70Hz。对力学试验前后桁架的各反射镜接口平面度进行了测量,结果显示其最大相对偏差为5.3%,平面度均优于0.15mm。得到的结果表明该桁架的刚度及尺寸稳定性均满足设计要求。

Design and alignment of support structure for off-axis multi-mirror system

A support structure with an adhesive truss was designed for a space camera with off-axis multi-mirror systems. The struts of this truss were manufactured with T700 made of carbon fiber composites, fittings were manufactured with titanium alloys, the adhesive was J133 epoxy resin and casting titanium fittings were bonded on both ends of the truss struts to provide interfaces for other subassemblies of the camera. The methods and steps for assist alignment equipment and gluing the subassemblies were described particularly. Firstly, preliminary assembly and alignment were done to ensure the precise locations of struts and fittings using the assistance equipment. Then, the formal alignment was performed with the help of locating pins, and the struts and fittings were restored in the correct initial positions and bonded with adhesives. Finally, the structure was solidified at room temperature for 5-7 days, and the assembly and alignment were finished after dismantling the assistance equipment and pins.The results of finite element analysis and vibration test indicate that the first-order natural frequencies of the truss and the lens supported by the truss are more than 90 Hz and 70Hz, respectively. Interfaces of mirror subassemblies were measured before and after vibration tests, and the results show that the flatness has been reached to 0.15 mm and the maximum relative error of interface flatness is 5.3%. The conclusion is that the stiffness and dimensional stability of the truss well meet the design requirements.