Form-finding And Wrinkles Characteristics Analysis Of Planar Membrane Structures

With continuous development and progress of the aerospace industry,membrane structures have been applied to various spacecraft structures due to its advantages of light weight,small volume after folding,and large area after unfolding.Membrane structures needs to maintain stable shape and surface accuracy to ensure stability and normal operation of structures when launched into space.Therefore,membrane structures needs to find membrane surface shape that meets structural requirements and balance conditions through form-finding analysis before launching.In addition,since flexural rigidity of membrane itself is very small,it is prone to wrinkles after being subjected to external load.The appearance of wrinkles seriously affect working performance of membrane structures.Therefore,it is of great significance to study characteristics of membrane wrinkles and how to suppress occurrence of wrinkles.For the square membrane structure with membrane surface size of 1m×1m,based on the two-time method for form-finding,form-finding analysis of membrane structures under tensioning structure with inner cables and tensioning structure with inner cable,outer cable and intermediate cables is carried out using ABAQUS finite element software.The effect of prestress and structural parameters in the membrane structure on fundamental frequency,effective area ratio and stress uniformity distribution is studied,and properties of membrane surface under two kinds of tensioning structures are compared and analyzed.The results indicate that under the same membrane surface prestress,fundamental frequency,effective area rate and stress distribution uniformity of tensioning structure with inner,outer cable and intermediate cables are lower than tensioning structure with inner cables.The explicit dynamic method is used to analyze wrinkles of rectangular membrane under shear displacement and square membrane under tensile load.The simulation results are compared with theoretical calculation results and experimental results in the literature to verify correctness of simulation model and results.The finite element analysis model of the square membrane structure is established,and the effect of increasing single tensile load and adding side cable structures on changing trend and characteristics of wrinkles is studied.It is found that adding side cable structures in membrane boundary can effectively suppress occurrence of wrinkles.Taking square membrane structure as research object,based on the explicit dynamic method,the effect of aspect ratio,value of angle,clamping width and local thickness of membrane in square membrane structure on wrinkles characteristics and out-of-plane deformation is analyzed.In addition,the effect of increasing clamping width and increasing local thickness on suppression and control of wrinkles is studied.The analysis results show that the number of wrinkles is relatively reduced,and the amplitude of wrinkles is significantly reduced with the larger clamping width.