为了探索振动环境对离轴反射式光学系统的影响, 本文对其系统结构部分进行了随机振动响应分析以及疲劳分析。利用有限元软件MSC/Patran建立光学系统结构的整体模型并进行模态分析, 以实际装配时基体框架前端连接法兰盘的连接孔部位作为边界条件, 通过对其每个节点的六自由度进行约束并进行模态响应分析。分析结果表明在X、Y与Z三个方向上平移及旋转变化量均很小, 满足空间环境中测量系统的精度要求。通过对光学结构整机部分在三个方向随机振动载荷作用下进行了有限元分析, 结果表明光学结构内部最大应力分别为151、267和280 Mpa, 都小于材料的抗拉强度, 且有足够的安全阈度。根据所选的铝合金A709的 疲劳曲线,以及应力响应PSD谱, 利用Palmgren-Miner假设, 对本文所选定的光学结构及其主框架结构在动力学环境下进行疲劳分析, 结果表明其满足系统使用要求。

In order to research the performance of off-axis reflective optical system against the dynamic environment, the random vibration and fatigue analysis is presented. The finite element model of optical system structures is established and its modal analysis is performed by the finite element software MSC/Patran. The boundary conditions are used as the connecting hole of the base frame which in the actual assembly. The analysis results are obtained by constraint to the each node, and it shows that the change of translation and rotation in three directions are very small. Content the accuracy requirement of the measurement system in the space environment. Finite element analysis of the optical system is carried out in the three directions random vibration load. The results show that the maximum stress of the optical system internal structure are 151, 267 and 280, respectively. According to the S-N fatigue curve with aluminum alloy A709, and the PSD Spectrum of stress response, made the fatigue analysis of off-axis reflective optical system against the dynamic environment with Palmgren-Miner assumption, the results meet the system requirements.