Design And Dynamic Optimization On Integrated Structure Of Satellite Main Bearing Structure And Optical Camera

Micro-satellite has been a research focus around the world for its striking features such as small size,lightweight,short development cycle,low cost,high concentrations of function and flexible launching method.These advantages are important and make it possible for building a satellite constellation,which is able to satisfy contingency remote sensing missions for short cycly revisit,global coverage and multi information source.Satellite structure,which provides,bears and transforms the payload of the whole system,is an important supportability system.It offers installation sites for carrying equipment and maintains the configuration of the entire satellite.The structural integration and lightweight design becomes important subject during satellite miniaturization.We experience some challenges in the process of researching on structure of Jilin-1 Smart-Video Satellite(or JSV Satellite).Based on the concept of satellite-payload integration design,integration of the central cylinder and the main load(the optical camera)is carried out and the integrated structure(IS)is then designed to make the load capsules and the service capsules set in a single structure.In this way,the functional density of the satellite structure is enhanced and the size of the satellite is reduced.Considering structural function,this paper conducts detailed optimization design of the IS from two aspects:(1)Main bearing structureThe IS is the main bobbin cylinder of the JSV satellite and also a part of the major load path,which provides installation sites for carrying equipment.This paper investigates the dynamic optimization of IS stiffness and random vibration response.First,from the structure sensitivity aspect and take the structure feature of carbon fiber composite into consideration,a multi-step optimization method is adopted to undergo a dynamic optimization of the IS considering the thickness and sequence of spreading layer.(2)Optical payloadThe integrated structure is a part of the camera optical system,which functions as the outer baffle that restrains the stray light.This paper optimize the IS design,including outer baffle structure design,optimum design of vane distribution and off-field light analysis.The system PST for the off-field light exceeds the required 10-5 level and completely satisfies the requirements of the JSV Satellite.Based on these optimization results,a finite element model of the entire satellite is built then a dynamic analysis of the entire satellite structure is conducted.The dynamic mechanical behavior including analytical vibration response and random vibration response is analyzed.It shows that the dynamic mechanical response meets the mechanical environment requirement of carrying equipment.In addition,stiffness is an important parameter in structure safety aspect.Considering the overload ratio and structure safety coefficient during launching process,this paper conducts a static analysis on the entire satellite.Furthermore,the safety margin of the satellite structure is calculated,which shows that the structure design meets the stiffness requirement.In order to verify the rationality of the structure optimization and testify the validity of finite element analysis result,this paper conducts a mechanical environment test for the sample satellite.After analytical and random vibration test on acceptance and appraisal circumstance respectively,experimental data are collected and they verify the validity of finite element construction and distribution.Based on the analysis above and experiment result,this paper proposed an innovative approach for optical macro-satellite structural design that fully meet its requirement on mechanical feature and function for corresponding structures.Therefore it is of high engineering value.