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Profile Accuracy Analysis Of Composite Membrane Antenna With Weak Stiffness

Posted on:2022-01-12Degree:MasterType:Thesis
Country:ChinaCandidate:Y M WangFull Text:PDF
GTID:2492306548968239Subject:Aeronautical and Astronautical Science and Technology
Abstract/Summary:PDF Full Text Request
The profile accuracy of reflecting surface of large deployable mesh antenna is affected by pillowing effect,that is because the flexible metal mesh does not have bending stiffness.In order to improve the profile accuracy,it is necessary to increase the complexity of the deployable back frame to reduce the pillowing effect,and so add weight to the antenna and reduce the deployment reliability.Obviously,if the metal mesh can have a certain bending stiffness,the pillowing effect can be alleviated.A kind of composite film material composed of metal mesh and some matrix material is proposed to replace the traditional metal mesh,so as to improve the profile accuracy of the reflecting surface of large deployable mesh antenna without significantly increasing the complexity of the deployable back frame.The research work of this paper focuses on the deformation characteristics of the weak stiffness composite film under transverse load,and the specific application in large deployable antenna remains to be studied in the future.The main work is as follows:1.Based on the basic theory of elasticity and plate shell theory,this paper established the deformation equation of circular composite membrane under transverse axisymmetric loads,and obtained the exact analytical solution of the deformed surface by combining with the boundary conditions.In order to obtain the analytical solution of the deformation of the simply supported circular composite membrane,the Timoshenko plate shell theory and the Kirchhoff thin plate small deformation assumption were adopted.The deformed surface of the circular composite membrane under multiple concentrated loads was solved by changing the axisymmetric concentrated load into the uniformly distributed load along the ring.The error between the theoretical results and ABAQUS results is less than 1%.2.The relevances among the RMS,Poisson’s ratio besides Young’s modulus was obtained by comparing the deformed surface of the circular composite membrane under different loads and different mechanical parameters and the standard paraboloid through the maximum deflection point and the two ends of the diameter of the circular composite membrane.The RMS of the circular composite membrane with different load distributions was analyzed,then the Poisson’s ratio of the composite membrane at the minimum RMS under different loading conditions was obtained.The study also found that by increasing the local bending stiffness of the circular composite membrane bearing point,the amount of loading forces required to achieve the same RMS value can be effectively reduced.3.Using silicone rubber and flexible epoxy resin as the matrix,compounded with warp-knitted metal mesh,five different weak-stiffness composite membrane test pieces were prepared.The deformation of different test pieces under central loading and multi-concentrated loading were studied experimentally.The measured values were compared with the finite element analysis values,and the error was within 5%,and the error with the theoretical calculation result was also within 5%,which verified this article The accuracy of theoretical calculations.
Keywords/Search Tags:deployable antenna, weak-stiffness composite membrane, circular thin plate, axisymmetric load, surface accuracy
PDF Full Text Request
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