Design And Analysis Of Deployable Truss-type Satellite Bus

With the development of high orbit communication satellite in the direction of large scale,high power and long life,on-orbit service technology has great application prospects in the future.However,the structure of traditional large-scale satellite bus is increasingly complex,which exists some limitations for on-orbit maintenance.The technology of deployable mechanism can change the dynamic characteristics of satellite bus to make faulty equipment reached for servicing and maintenance,which has become a development trend of Aerospace Technology.At present,there are few researches on the technology of deployable satellite bus.Aimed at the requirement of on-orbit servicing for large synchronous communication satellite,the paper takes repeatedly deployable truss-type satellite bus as the research object and carries out the research on configuration design and optimization method,structure optimization and design,kinematics and dynamics analysis and prototype development and function verification.In order to design a deployable satellite bus with less quality,high stiffness and inertia change rate,according to main frame structures and main bearing structures of traditional satellite buses,the paper proposes six kinds of repeatedly deployable truss-type satellite buses.Honeycomb panels is equivalent panels with the honeycomb equivalent theory.The structure design and finite element analysis of six configurations are carried out by Solidworks software and ANSYS Workbench software.The main performance indexes of these satellite buses,such as mass,inertia change rate,utilization rate of fairing area,deployed surface area ratio,vibration frequency in folded and deployed state,equipment layout effect and complexity of deployable mechanism are analyzed.Each performance index's weight is obtained by the chromatography analysis method,and the scheme with better comprehensive performance is selected using the fuzzy synthetic evaluation method.The height of the satellite bus and the parameters of the honeycomb panels on performance indexes is further analyzed and the corresponding parameters are optimized.The parametric finite element models of the satellite bus in folded and deployable state are built by ANSYS Workbench software.The thickness of the truss is used as design variable.The fundamental frequency is used as constraint condition.The optimization results are obtained by using multi-objective genetic algorithm.And the corresponding parameters are optimized.According to simplified diagram,the calculation result of the degree of freedom of the deployable mechanism is 1.Calculate the length of each member of the truss,the detailed structure design of the satellite bus is completed,and a 3D printing model is manufactured to verify the function of deploying and folding.A compact,lightweight and repeatable cone-rod locking mechanism is designed,of which static simulation,kinematics simulation and connection stiffness analysis a re finished.A prototype is manufactured to verify the function of joining and separating.The kinematic and dynamic characteristics of the deployable truss-type satellite bus are analyzed.Based on the D-H method and ADAMS simulation method,the kinematics model of the satellite bus is established,the angular displacement,angular velocity and angular acceleration of the deployable mechanism are obtained.The deployable process of the satellite bus is stable,and the impact is small.Using ANSYS Workbench software to analyze the dynamic characteristics of the satellite bus.Through the modal analysis,harmonic response analysis and random vibration analysis,it is concluded that the satellite bus has good stiffness and strength in the vibration environment.