Design And Analysis Of Bistable Prestressed Film Laminated Shell Structures

The multistable structure is a new type of deformable structure with many stable configurations.Each stable configuration of the structure can bear a certain load,and remain stable without the need for sustained energy input.A multistable structure can be achieved from a stable configuration buckling jump to another stable configuration in less energy input,the deformable characteristic and variable stiffness characteristic in the configuration transformation,has a good application prospect in morphing structures.At present,the research of multistable structures is mostly concentrated on bistable composite laminates and bistable prestressed metal shells,and little attention has been paid to the preparation of bistable prestressed film laminated shells.A bistable film laminated shell is light and soft,its stiffness is small relative to bistable metal shells and the snap-through needs less energy input.It overcomes the size effect of bistable composite laminates,has a significant advantage in the design of mini bistable structures.This paper studys bistable prestressed film laminated shell,from the aspects of experimental preparation,mechanical analysis and application design of bistable structure.In this paper,experiments for bistable prestressed film laminated shell are carried out.In order to meet the requirements of the preparation of b istable film laminated shells,a biaxial stretching device with displacement loading is designed,and the adhesive between the layers is screened.In this paper,a variety of anti-symmetric bistable film laminated shells are made,curvature and centeral snap-through critical load in two stable configurations of the shells are tested respectively.And the mechanical properties of bistable thin film laminated shell are analysed.The configurations of anti-symmetric bistable film laminated shells are analysed in regular and irregular tensile cases.The effects of stretching distance and shell size(aspect ratio,interlayer)are analysed;It is found that the curvature of the laminated shell is increased proportionally with the pre-stretched distance increasing.Size of laminated shells has little effect on the curvature of the laminated shell.A theoretical prediction model is established for the laminated shell structure,and the finite element method is used to calculate the results.The calculated results are compared with the experimental results.The error between calculated results and experimental results is within 7%.Finally,based on the characteristics of bistable film laminated shell structure,the bistable thin film laminated shell structure is combined with microstr ip antenna,and the bistable reconfigurable antenna is designed.The antenna pattern and operating frequency of the bistable reconfigurable microstrip antenna are calculated by means of electromagnetic simulation software.The influence of the radius of curvature of the configuration on the antenna pattern is investigated.A bistable reconfigurable antenna is made by screen printing process,the performance of the antenna is tested and the feasibility of the design is verified.