Structure Optimization Study Of 2m Space Optical Remote Sensors Large Aperture Mirror Components

In order to improve the resolution and imaging quality of the remote sensor,it is necessary to increase the effective light aperture of the primary mirror.More stringent requirements and higher manufacturing ability are adopted for designing supporting structures.The structural optimization of the 2m aperture primary mirror component of a large-scale optical load project is studied.Firstly,the mirror body is preliminarily designed by empirical design method.The form of three-point support on the back,the triangular lightweight holes type,the semiclosed form on the back is selected.Genetic algorithm is used in the process of topology optimization and parameter optimization,and optimization time is reduced to 5%.The weight of the lightweight mirror body is 273 kg,the lightweight rate is 85.7%,both meet the design requirements.The adhesive tape length of the cone sleeve is 70 mm.The mass of each cone sleeve is 4.7kg which meets the quality requirements.Secondly,two initial schemes of flexible support structures are proposed and optimized by decoupled from the mirror body.Optimize time is reduced from 15 min to30s.When the optical axis is horizontal,the surface error of the optimal design caused by gravity,temperature and assembly error is less than the error distribution index after comprehensively considering its static,dynamic and fatigue characteristics.The firstorder frequency of the mirror assembly is 117 Hz and it meets the design requirements.The random vibration fatigue life of the flexible support structure is 95300 s,and fatigue failure will not occur before entering orbit.Finally,the surface accuracy,rigid body displacement and tilt angle changes,and random vibration fatigue life of the 2m mirror are verified by vibration and temperature tests.The change of rigid body displacement caused by stress relief in the component is much less than the design index requirements of 15μm,and inclination angle meets the design index of less than 3.5".Maximum dynamic stresses of the support structure under sine vibration and random vibration are 122 MPa and 286 MPa,respectively.Both are lower than the material micro-yield stress of 650 MPa.The result of the random vibration fatigue is 87050 s.The relative error with the simulation analysis results is within 10%.After simulation analysis and experimental verification,it can be seen that the performance of the mirror assembly meets the design requirements.The design method adopted in this paper can greatly improve the design efficiency and accelerate the project.