Field Coupling Model,Design Method And Experimental Study Of Space-Borne Electrostatically Controlled Membrane Reflector Antenna

There are many key technical issues in the development cycle of the electrostatically controlled membrane reflector antenna,such as the form-finding analysis,multi-field coupling model establishment and solution,membrane surface precision adjustment and physical model making.This article has conducted in-depth research on the above issues and the main works can be described as follows:1.A form-finding analysis strategy for the electrostatically controlled membrane reflector antenna with an improved force density method is proposed.Firstly,the stress equivalent nodal force of the triangular membrane element is obtained by the principle of virtual work.The force density equation of the membrane stress equivalent to the cable is derived according to the nodal force decomposing into the side of the triangle.Then the improved force density balance equations of the electrode surface tension structure and the membrane reflector tension structure are derived,and the corresponding iterative solution strategy is given.Considering the deformation of the truss will affect the cable-membrane tension level and the accuracy of membrane reflector surface,a method for form-finding analysis of the cable-membrane-truss structure is proposed.Finally,considering the relative sliding between the cable and the membrane,a sliding cable-membrane structure model is proposed.Simulation examples demonstrate the effectiveness of the improved force density method for the form-finding analysis of the electrostatically controlled membrane reflector antenna and the necessity of considering the sliding cable for the cable-membrane structure analysis.2.A field coupling model of the electrostatic field and membrane structure deformation field based on the energy variation principle is proposed.Firstly,the uniformity of the electrostatic field and the membrane structure deformation field is discussed from the energy point of view.Then the electric field potential and the membrane displacement are regarded as unknown quantities,the coupling equations of the field coupling model are derived which can be solved by a system of nonlinear equations.Finally,the field coupling model is used to analyze the relationship between the random error of the electrode surface and the precision of the membrane reflector surface.Simulation examples verify the accuracy and efficiency of the field coupling model.3.A method for adjusting the precision of the space-borne electrostatically controlled membrane reflector antenna based on electromechanical integration is proposed.Firstly,the physical optics method,the thermal energy conservation law and the electrostatic field-membrane deformation field are used to establish the electromechanical integration model,the effects of membrane surface errors and feed errors on the electromagnetic field are also analyzed.Then taking the electrode voltage and cable force as design variables and the maximum directivity coefficient of the antenna as the objective function,An electromechanical integrated surface precision adjustment model is developed.Finally the electromechanical integrated calculation formula based on the isoparametric element is derived.Simulation examples verify the effectiveness of the electromechanical integrated surface precision adjustment model and the efficiency of the isoparametric element in the electromechanical integration analysis.4.The physical model of the electrostatically controlled membrane reflector antenna was developed and experimented.Firstly,the 2m and 5m electrode surface tension structure design are carried out by using the form-finding analysis method proposed in this paper.The production process of cable section cutting and networking,film electrode surface cutting and pasting are introduced,and high-precision non-contact photography is used.The measurement equipment measures the accuracy of the electrode surface profile to verify the effectiveness of the form-finding method.Then,the 2m membrane reflector surface was designed and fabricated,and the finite element model including the physical model information was established by the reset balance method.Finally,the electrode voltage and cable tension are optimized according to the finite element model and the voltage cable force coordination adjustment model.The optimized electrode voltage and cable tension value are applied to the physical model to adjust the precision of the physical model profile.The experimental results verify the effectiveness of the adjustment method.5.A high precision film reflective surface thermal forming method is proposed.Firstly,the feasibility of the thermal forming of the reflective surface of the film is theoretically verified,and the essence is that the film creeps at high temperature.Then,the thermal forming simulation and experiment of the 0.3m diameter thin film reflective surface were carried out to verify the feasibility of the thermal forming scheme,and then the 5m diameter thin film reflective surface was formed by thermal forming method.Finally,the precision of the reflective surface of the film was measured and adjusted by using high-precision photogrammetric equipment.The experimental results verify the effectiveness of the film thermal forming method.