Research On Mechanical Properties And Thermal Deformation Of New Negative Poisson's Ratio Honeycomb Reflector Antenna

Satellites are widely used as important tools in modern military,civil and aviation fields.The satellite reflecting surface is used to collect or transmit signals as one of the important equipment of satellites.At present,satellite-borne satellite antennas are generally formed in a parabolic shape.Honeycomb sandwich panels are often used to make reflective surfaces,the honeycomb sandwich panel is composed of an upper skin,a lower skin and a honeycomb core layer.The honeycomb core cell uses a hexagonal honeycomb structure,and the hexagonal honeycomb cell is a typical positive Poisson's ratio structure,with the in-depth study of the structure of negative Poisson's ratio in recent years,the superiority of negative Poisson's ratio becomes more and more obvious.Based on the study of the mechanical properties of the negative Poisson's ratio structure,the negative Poisson's ratio structure is applied to the satellite reflecting surface,and multi-objective optimization is performed with the reflection surface accuracy value as the optimization target to improve the reflection accuracy of the reflection surface.The main research contents of the paper are as follows(1)Derivation of mechanical properties of honeycomb cell structure.Based on the theory of elasticity and engineering mechanics,the cell wall of a honeycomb cell is equivalent to an EulerBernoulli beam,and the displacement formula of the honeycomb cell structure under a load is obtained by combining the principle of virtual work to establish a new negative Poisson's ratio Analytical formulas for Poisson's ratio and equivalent elastic modulus of honeycomb cell structure.The cellular cell is equivalent to an anisotropic cell wall of the same size as the cellular cell wall,and the equivalent torsional stiffness of the cell is derived by using the same principle that the honeycomb cell and the thin plate change performance under the uniformly distributed torque.(2)New negative Poisson's ratio honeycomb cell structure design parameters affect its mechanical properties.The influence of the design parameters of the honeycomb structure on the mechanical properties of the honeycomb cell is studied.The mathematical expressions of the Poisson's ratio,equivalent elastic modulus,and equivalent torsional stiffness of the honeycomb cell structure with negative Poisson's ratio are derived through theoretical derivation.The formula is input into the Matlab software to obtain a graph of each mechanical property changing with the geometric dimensions of the honeycomb cell.Provide a theoretical basis for subsequent cell structure optimization.(3)Finite element simulation of honeycomb cell structure.The finite element software was used to simulate and analyze the modal frequency,static deformation of the structure with negative Poisson's ratio,and compare the shear resistance of the hexagonal honeycomb panel.The data points of the structural design parameters of the honeycomb cell are collected by parameter experimental design method and Latin hypercube sampling.Based on the collected data,the influence of the structural design parameters on the modal frequency and static deformation of the cellular cell is studied.Using the RBF approximate model fitting,the relationship between cell parameters and static deformation is obtained and the correctness of the RBF model is verified.The sequence quadratic programming method is used to solve the RBF model,so as to obtain a reasonable combination of cellular parameters.(4)Simulation and optimization of the thermal deformation of the satellite reflection surface.The honeycomb cell structure with negative Poisson's ratio is applied to the reflection surface of the satellite antenna,and the thermal deformation of the reflection surface under a uniform temperature field is obtained by finite element software simulation.With the accuracy value of the reflective surface profile as the optimization target,the design parameters of the negative Poisson's ratio structure and the skin lay angle as design variables,the particle swarm optimization algorithm was used to obtain the best size and the best lay angle of the cell structure.The results show that the accuracy value of the reflective surface is increased by 22.6%.