Equivalent Mechanical Property and Dynamics Crushing of a Novel Bi‐Material Structure with Negative Poisson's Ratio: Analytical and Numerical Solutions

Compared with the single material negative Poisson's ratio structure, the bi‐material cell design can combine the negative Poisson's ratio characteristics with the excellent properties of the material combination, so that the structure has better mechanical properties while retaining the negative Poisson's ratio characteristics. A novel bi‐material cell with concave curved edge and negative Poisson's ratio is proposed. The analytical expression of the equivalent Poisson's ratio was obtained based on the energy method theory. The comparison between numerical results and theoretical solutions shows the correctness of the proposed method. A negative Poisson's ratio multicell structure of the bi‐materials is constructed by using the proposed cell and the impact dynamic performances were studied by numerical method. The comparison of experimental and simulation results shows the effectiveness and feasibility of the numerical method in this paper. Influences of central angle and curvature radius ratio on the equivalent Poisson's ratio were studied. The influences of bi‐material modulus ratio and curvature radius ratio on crushing deformation failure, stress–strain curve, platform stress, and energy absorption effect were discussed in detail. The results show that the bi‐material structure has better dynamic properties and energy absorption effect.