Mechanism Design,Structural Analysis And Experimental Study Of Large Hoop Truss Deployable Mesh Reflector Antennas

Aiming at the development requirements of large aperture(high gain),high precision(high frequency band),high stiffness and light mass of future space-borne antennas,this study conducts research on large hoop truss deployable mesh reflector antennas.With innovative design as the core,theoretical analysis as the key and experimental verification as the foundation,in-depth researches have been conducted from the aspects of mechanism design,form-finding design,thermal stability design and prototype experiment.The main works can be described as follows.1.A design scheme of H-ring deployable truss structure with high storage ratio and light mass is proposed.Firstly,to solve the problem of low storage ratio in the height direction of Astro Mesh deployable mesh antenna,a single-ring deployable antenna truss(referred to as H-ring structure)with bi-directional deployable function is proposed,which can increase the height storage ratio by nearly twice.Secondly,the deployable mechanism and driving mode of the hoop truss are analyzed in detail,and the motion characteristics are preliminarily verified by making a simple scaling model.Then,a comparative analysis is conducted with typical hoop truss,indicating that the proposed truss has the advantages of high storage ratio and light mass.Finally,a kinematic analysis model for the deployment process of the proposed truss is established,and the motion characteristics of the deployable truss are analyzed,verifying the deployment performance of the hoop truss.2.A design scheme of H-cube deployable truss structure with high storage ratio and high stiffness is proposed.Firstly,in response to the problem that the stiffness of H-ring structure scheme is low and it is difficult to meet the requirements of future large aperture antennas,a double-ring deployable antenna(referred to as H-cube structure)with bidirectional deployable function is proposed.On the one hand,the use of a double-ring structure significantly improves the stiffness of the antenna structure.On the other hand,the stowed height is approximately one-third of the deployed height,so the storage ratio is much higher than that of similar antennas.Secondly,a detailed design and analysis are conducted on the deployment driving mode of the truss mechanism.Then,compared with the same type of antennas,it is shown that the proposed scheme has the characteristics of high storage ratio and high stiffness.Finally,a kinematic analysis model for the deployment process is established,and the deployment performance of the proposed truss is verified through the analysis of the deployment process.3.A cable-net form-finding design method considering small deformation of hoop truss is proposed.Firstly,based on the analysis of the stiffness characteristics of the hoop truss,a cable-net tension design criterion for minimizing the deformation of the hoop truss is obtained.Then,a form-finding design model based on the cable-net tension design criterion is proposed.Under the premise of ensuring the equal tension of the cable net in effective zone,the boundary cables are redesigned to achieve uniform force on the hoop truss,so as to reduce the deformation of the hoop truss.Finally,numerical examples verify the correctness and effectiveness of the proposed model and method.4.A thermal stability design strategy of multi-material composite cable-net structure is proposed.Firstly,the cable element is simulated by tension bar,and the mechanical model of cable-net structure is established.The mathematical expressions of nodal position,cable force and surface accuracy under temperature load are derived.Secondly,an optimization design model is established,which takes the material type of cable element as the design variable,surface accuracy as the optimization objective and cable force as the constraint condition.Then,genetic algorithm is used to solve the optimization model to obtain the material type of each cable element.Finally,numerical examples verify the correctness and effectiveness of the proposed model and method.5.Two prototypes of H-ring and H-cube deployable antenna structure are developed and experimented.Firstly,the model is virtualized based on virtual prototype technology.Secondly,the blueprints are drawn,the components are manufactured,the models are assembled and two hoop truss physical models of 5 m aperture antennas are developed.Then,the corresponding cable-net structures are designed and manufactured.Next,the cable-net structures are assembled with the trusses to form two antenna structure prototypes.Finally,experimental results verify the feasibility and effectiveness of the novel scheme and design method proposed in this study.