工程中将实际的非线性系统近似为线性系统,用线性分析方法对所研究的对象进行分析往往会带来较大的求解误差。介绍了产生结构非线性的主要因素,并在接触理论基础上,对某空间相机反射镜组件进行了合理的有限元建模。采用接触非线性分析方法对螺钉预紧时反射镜的响应及在自重和温度载荷作用下反射镜的变形进行了分析。通过比较线性分析与非线性分析的结果表明:采用非线性分析的结果更接近实际;在空间相机的工程分析中,对某些接触部位采用非线性的分析方法可以提高分析精度。 In the project, the actual nonlinear system is approximated as a linear system. Analyzing the research object by linear analysis often leads to large solution error. In this paper, the main factors causing the nonlinearity of the structure are introduced. Based on the contact theory, a reasonable finite element model of a space camera mirror assembly is established. The contact non-linear analysis method was used to analyze the response of the mirror when the screw was preloaded and the deformation of the mirror under the self-weight and temperature load. By comparing the results of linear analysis and non-linear analysis, the result of nonlinear analysis is more realistic. In the engineering analysis of space camera, the non-linear analysis method of some contact parts can improve the analysis accuracy.