DESIGN AND WAVE PROPERTIES OF RECONFIGURABLE MECHANICAL METAMATERIALS

The bending beam bistable structure in mechanical metamaterials has attracted extensive attention in recent years due to its strong active control and high control accuracy. In this paper, a hexagonal bistable structure is designed by using the instability of the centrally compressed bending beam. Firstly, the equivalent bending beam model is established and the basic principle of the bistability of the structure is proved based on the differential equation of beam deformation and the principle of minimum energy. Then, the influence of structural geometric parameters on its mechanical properties is studied by finite element numerical calculation. The range of structural geometric parameters with self recovery and bistable properties is obtained respectively, and the phase diagram between geometric parameters and mechanical properties is drawn. At the same time, the controllable deformation ability of the reconfigurable structure helps to adjust the dispersion characteristics, numerical simulation is used to study the dispersion relationship of the structure with bistable characteristics under the two configurations of tension and compression, and the effects of different structural geometric parameters and configuration changes on the band gap position and range of the structure are compared and analyzed. After that, the frequency response analysis of the periodic structure composed of different configuration cells is carried out to verify the accuracy of the band gap calculation. In conclusion, the mechanical properties, dispersion properties and frequency response analysis of the hexagonal reconfigurable structure show that the overall performance of the structure can be actively controlled through the design of the geometric parameters of the structure, which provides a reliable path for the research and analysis of the elastic wave metamaterial structure with reversible design.