The Design And Analysis Of Flexure Hinges For The Solar Sail

China has a significant aerospace industry and achieves remarkable achievements in the field.Solar wing is the main energy source of spacecraft entering space and plays a key role in operation.Its deployment process has certain influence on the control of spacecraft.In recent years,incidents of spacecraft accidents have taken place due to the expansion of the solar wings,posing a threat to the normal operation of the spacecraft.The solar wing is hinged by several solar panels.Due to the existence of gaps in the traditional hinges,there is friction and wear during the process of rotation.It is a cause of some lubrication and vibration,and affects the attitude control and normal operation of the spacecraft.Flexible hinges can avoid these problems and provide the driving force by using of deformation of the material itself.The concept of constraint space,intersection point and cross distance is defined based on screw theory and FACT theory in order to design a flexible hinge with a single rotational degree of freedom.Under the constraint condition of the bar and the plate,the flexible hinge with a single degree of freedom is turned into the system classification by considering the different influences of constraint position and deformation form on flexible unit.On this basis,the idea of adding restraint of bar and plate is given.Combined with the series-parallel relationship of flexible units,three kinds of single degree of freedom flexible hinges with large-angle are designed.In order to analyze the mechanical properties of the designed flexible hinge and obtain better mechanical properties,flexible hinge mathematical models of rotational stiffness and radial stiffness were established by using a pseudo-rigid body method,energy method and series-parallel relationship.Taking the dimension parameter of the flexible hinge as the design variable and using the boundary constraint,the size relation and the performance constraint as the constraint conditions,the optimal mathematical model of flexible hinge is established with the aim of improving the rotation ability and ensuring a certain radial rigidity.The design parameters of the flexible hinge are optimized by multiobjective optimization method.By comparing the performance of flexible hinges before and after optimization,the rotational flexibility and radial stiffness of the optimized flexible hinges have been significantly improved.The finite element model of the flexible hinge was established in Ansys.The rotational stiffness and radial stiffness of the flexible hinge were analyzed by simulation.The correctness of the stiffness model was verified by comparing the theoretical value with the simulation value.After building an experimental platform,torque sensor,eddy current displacement sensor,NI and other equipment are used for data acquisition and research.The rotational stiffness and radial stiffness of the modular flexible hinge are tested.Through the stiffness test,the correctness of the stiffness model about flexible hinges is further verified.Through Solid works(3D modeling software)a solid model of satellite components,solar panels,flexible hinges and other key components was established.Adams dynamic software was used to simulate the unfolding and locking process of the solar wing.After analysis,the solar wing can be smoothly deployed and locked.In general,the smooth development of the solar wings is achieved by replacing the traditional hinges with flexible hinges.A more in-depth study was carried out in the theory,simulation and experimental aspects.It provides the design ideas for the design of flexible hinges with single degrees of freedom and provides the theoretical basis for the design and optimization of the three flexible hinges.At the same time,the experimental analysis of the combined flexible hinges is carried out,and the dynamic analysis of the solar wings is carried out.A smooth start and lock are achieved.