Design Of A Programmable And Tunable Metamaterial Structure With Negative Poisson’s Ratio

The research and manufacturing of new materials is significant to the development and progress of modern industry,China has clearly proposed to focus on the development of the new generation of new materials exhibition industry in its 14 th Five Year Plan and vision 2035.Metamaterials,as an important branch of new material technology,have important research values and wide application prospects because of their excellent properties,designable and tunable characteristics,which are far beyond the natural materials.In this paper,Mechanical metamaterials are studied,which belong to one of the many disciplines of metamaterials,and a novel programmable and tunable metamaterial structure with negative Poisson’s ratio is proposed.The design idea combines the optimization algorithm with the artificial adjustments together,the initial structure with negative Poisson’s ratio close to-1 is obtained by combining the asymptotic homogenization method with the topology optimization method firstly,and the key parameters of its geometric features are extracted;then,by artificial design and Python,the parametric modeling,GUI interface development and calculation script writing of thermal stress homogenization method for various cell types are completed on ABAQUS platform successively.It not only realizes the function of setting up user-defined cell quickly by inputting a few parameters,but also could inversely deduce the cell structure under the specified Poisson’s ratio,so as to realize the precise control of the Poisson’s ratio of the cell,and truly realizes the programmability of the negative Poisson’s ratio metamaterial structure and the tunability of its mechanical properties.Finally,a series of structures with practical application value are designed by using the negative Poisson metamaterial,including double curvature structure,three-dimensional square tube,circular tube structure,three-dimensional orthotropic structure and a tension-compression anisotropic Poisson’s ratio structure.The last structure breaks through the traditional mode of single-step deformation by virtue of contact nonlinearity and geometric nonlinearity,and realizes multi-step deformation of the cell with negative Poisson’s ratio and the second change of Poisson’s ratio from negative to positive.It can be used in multistage shock absorbers,energy absorbing structures or mechanical logic gates.