大口径轻质反射镜采用柔性支撑结构可以降低外界力载荷、惯性载荷及热载荷的负作用，从而保证光学系统的成像质量。为消除加工、检测与系统装调过程的定位误差，研究了应用于计算机控制能动磨盘加工(CCAL)技术抛光的柔性限位支撑模型。利用有限元分析软件(Ansys)，分析1.8 m轻质镜采用柔性限位支撑时， CCAL技术抛光引起轻质镜的最大倾斜量、最大主应力以及主镜面变化范围，对支撑盘的口径及位置进行了优化设计，模拟仿真18点弹簧在不同压缩量下的镜面变形。仿真分析结果表明，柔性限位支撑的结构刚度、轻质镜底板倾斜量满足能动磨盘加工条件，最大主应力强度远小于主镜的许用应力，主镜面变形符合加工要求。

Large-diameter lightweight mirrors with a flexible support structure can reduce the external force loads, inertia loads, heat loads and so on to ensure the quality of the optical imaging system. In order to eliminate the positioning error during polishing, testing and installation process, a novel support technology named flexible displacement support model is used in CCAL polishing. Based on finite element analysis software Ansys, the greatest amount of tilt, the maximum principal stress and the deformation of 1.8 m lightweight reflector caused by CCAL polishing based on the flexible displacement support are analyzed, the simulation and optimization of the diameter and distance of the restriction pad are finished, and the deformation of 1.8 m lightweight reflector in different amounts of springs compression is simulated. Simulation results show that the stiffness of flexible support structure, amounts of tilt of reflector floor plate can meet the polishing condition, maximum principal stress intensity is much smaller than the yield stress of the primary mirror, and the deformation satisfies the processing requirements.