胶层固化对反射镜面形影响的仿真与试验

Abstract

The effect of shrinkage stress induced by adhesive curing on a reflective mirror surface was analyzed when the thick adhesive layer was used to joint optical elements. Firstly, the principle of tensile stress induced by adhesive layer to optical elements during adhesive curing was analyzed and the main factors of generating shrinkage stress were obtained. Then, a finite element model of the reflective mirror set was constructed. The finite element analysis was carried out by using the thermal-to-shrinkage analogy and the thermal modeling tools were used to compute the adhesive curing shrinkage. The curing shrinkage was substituted by low temperature concentration, but the Coefficient of Thermal Expansion( CTE) value of the adhesive could not be taken place by the coefficient of adhesive shrinkage directly. After converting the coefficient of adhesive shrinkage to the equivalent CTE value, the analysis results are accord with the test results. Finally, the improved glue scheme was put forward on the basis of the analysis results. The experiment results indicate that the reflective mirror surface deformation( PV value) has decreased from 0.547 to 0.064, and the RMS value decreased from 0.127 to 0.038. This results mean that the effect of shrinkage stress in adhesive curing processing on the reflective mirror surface has improved greatly.