三种支撑方式下反射镜镜面静力分析

Static Analysis of Reflector Mirror in Three Kinds of Support Structure

为了分析不同的反射镜支撑结构对反射镜面型精度的影响,利用有限元法分析计算环形支撑、三点支撑及钢带支撑三种支撑结构下的反射镜镜面的应力与位移变化量.根据不同的支撑方式,反射镜受力的不同进行边界条件设定,环形支撑,对整个圆加以约束,三点支撑,圆选择三点加以约束,钢带支撑边界条件选择下端圆弧固定加以约束.研究结果表明:环形支撑得到反射镜的最大应力为0.004 4 MPa,三点支撑得到反射镜的最大应力0.047 7 MPa,钢带支撑得到反射镜的最大应力为0.024 5 MPa,带式支撑的镜面应力位移变化较为均匀,相比较前两种支撑方式,钢带支撑较为可行.

In order to analyze the influence of the support structure on the accuracy of reflector, finite element analysis is used to calculate the stress and displacement variation of the reflector with three kinds of support structure：circle support, three-point support and steel belt support. According to the different ways of support, different boundary conditions of mirror force are set. For ring support, the whole circle is restrained, for three-point support, three poits of a circle are restrained, for steel belt support, the bottom circle is fixed to restrain it. The results show： The stress of the reflector with ring support is 0.004 4 MPa,the stress of reflector with three-point supporting is 0. 047 7 MPa,the stress of reflector with steel belt supporting is 0. 024 5 MPa. It is concluded that the cloud of mirror changes in the steel belt type support is relatively uniform. Compared to the first two support, the steel belt supporting is more feasible.