红外导引头光学性能有限元分析

Finite Element Analysis for Optical Property of Infrared Lead

对红外导引头进行光学性能有限元分析,考核结构在动力学环境下的光学系统变形是否满足成像要求。本文利用模型修正的有限元方法对红外导引头进行了光学性能分析。首先,在建模过程中采用复合材料单元模拟构件之间连接特性。进而,通过反复修改复合材料单元的特性参数使模态计算与试验结果相一致,获得正确和有效的有限元计算模型。最后,对修正好的红外导引头有限元模型进行瞬态振动与过载仿真计算,获得光学系统各光学元件镜面变化结果。分析结果表明:结构在各动力学环境工况下的光学镜面相对转角小于3″,光学镜面位移值小于1μm。红外导引头光学系统在动力学环境下的镜面变形及倾角均在许用范围内,光学性能满足成像要求。

Optical property of infrared lead was solved by finite element analysis to make sure that the deformation of optical system under dynamic environment meets imaging requirement. The optic property of infrared lead was analyzed by means of finite element model based on model updating. First, composite material element was created to simulate the connection relation between parts, and then property parameter of composite material element was modified repeatedly to make the result of tested model and calculated model identical. Therefore, correct and effective model finite element was achieved. Finally, the simulation calculation of transient vibration and overload was carried out for the updated finite element model of Infrared lead. Analysis result indicate： mirror face deflection of structure under dynamic environment less than 3＂, and mirror face deformation of structure under dynamic environment less than 1 p.m. The mirror face deformation and deflection of infrared lead optical system under dynamic environment were within the allowable range, and the optical property of infrared lead meets the imaging requirement.