Dynamic Characteristics Of Wrinkled Membrane

In recent years,tensioned membrane structures have been widely used in various space crafts.Due to the non-uniform tension,process defects and other factors,the membrane structure in practice is prone to wrinkle.The wrinkles will reduce the performance of the membrane structure,and change the dynamic characteristics of the structure.At present,a large number of theoretical and experimental studies have been carried out on the characteristics and mechanism of wrinkled membrane structures.However,little attention has been paid to the dynamic characteristics of wrinkled membrane structures,especially on the propagation properties of elastic waves in the wrinkled membrane structure.Based on the theory of stability,the Bloch’s theorem is applied to the membrane structure with periodic distributed wrinkles.The energy band of the membrane structure is calculated and the propagation characteristics of the elastic wave in the wrinkled membrane structure are studied by transient simulation.The main contents are as follows:1.A numerical simulation method to calculate the band structure of wrinkled membrane is proposed.Based on the wrinkle analysis,the ABAQUS finite element software is developed by using MATLAB program.The Bloch boundary condition is realized and the energy band characteristics of the membrane structure could be calculated efficiently and accurately.2.Based on local resonant mechanism and Bragg scattering mechanism,a membrane with periodic cell structure can be used to tune the propagation of elastic wave.The wrinkle characteristics of the membrane structure are studied by finite element method.The critical buckling load and the stress field,displacement field and reaction force of the boundary in postbuckling are obtained.3.The energy band of the membrane with periodic cell structures under different structure and material parameters are calculated by ABAQUS.Then,the energy band of the loaded membrane structure is obtained under the stress field without wrinkles.4.The energy band of the wrinkled membrane structure is studied.When the applied load exceeds the critical buckling load of the membrane structure,wrinkles form on the membrane structure.At the same time,the bandgap of the wrinkled membrane structure is calculated.The complete bandgap of the structure disappears and the directional bandgap is enhanced.The transient wave propagation at different frequencies is obtained by transient simulation.The method of tuning the elastic wave propagation in membrane structure by wrinkles is proposed.5.The numerical simulation of the wrinkling of space membrane antenna in engineering is carried out.The optimized parameters of the boundary configuration and the magnitude of the tension are obtained,and the effects of various local structures on wrinkles are analyzed.Finally,the wrinkles of the multilayer structure are numerically simulated.The location,wavelength and amplitude of wrinkles are obtained,which provide important reference for the design of space membrane antenna.