空间光学遥感器光学镜面有限元分析结果的后处理

光学镜面是空间光学遥感器的重要组成部件,刚体位移和面形误差是评价其环境适应性的重要指标。介绍了一种从Pantran/Nastran软件的有限元分析结果中提取光学镜面的刚体位移和面形误差的方法。首先对Patran输出的原始数据进行预处理,消除原始数据误差;然后采用坐标变换法计算光学镜面的刚体位移,并通过法方程法直接进行求解,没有出现病态矩阵问题;最后通过球面方程拟合法计算光学镜面的面形误差,将球面拟合问题转换成3变量最优化问题再进行处理,并采用高斯-牛顿法进行数值迭代求解。经工程实践证明,该方法具有计算简洁准确、计算速度快等特点。

Post-processing of FEA Results of Optical Mirrors for Space Remote Sensor

Optical mirrors are the important components of a space remote sensor. Their rigid body displacement and surface figure errors are the key indexes for evaluating their environment adaptability. A method for extracting the rigid body displacement and surface figure errors of mirrors from the Finite Element Analysis (FEA) result by the Pantran/Nastran software is presented. First, the raw data output from Patran/Nastran are preprocessed to eliminate their error. Then, a coordinate transformation method and a method of normal equations are used to calculate the rigid body displacement. No ill conditioned matrix problems are found in calculation. Finally, a spherical fitting method is used to calculate the surface figure error. The spherical fitting problem is converted to the optimization problem with three variables and the Gauss-Newton method is used to carry out numerical calculation. The experimental result shows that this method is concise, accurate and fast.