Study On Mechanical Properties Of Gradient Negative Poisson’s Ratio Arc-edge Honeycomb Structure

A new type of multi-arc curved edge concave honeycomb structure with adjustable Poisson’s ratio is proposed,and combined with the gradient design method,the gradient multi-arc curved edge concave honeycomb structure is constructed in this paper.The analytical expressions of equivalent Poisson’s ratio and equivalent elastic modulus of multi-arc curved concave honeycomb structures are given by using the energy method,the theoretical results are verified by the finite element method,and the finite element results are in good agreement with the analytical solutions.The effects of cell geometric parameters on the mechanical properties of materials are discussed.The calculation expression of the relative density of the structure is given,and the influence of structural parameters on the relative density is discussed.The research results provide a reference basis for the subsequent internal concave cell design and theoretical analysis.In the aspect of impact dynamics,the finite element models of homogeneous honeycomb and gradient honeycomb are constructed by ABAQUS finite element software,and the in-plane impact dynamics is simulated by explicit dynamics module.The deformation collapse mode,dynamic response curve and energy absorption curve of honeycomb structure under different impact velocities are given,and the platform stress of gradient honeycomb structure is calculated.the effects of Poisson’s ratio,impact velocity and gradient arrangement mode on the impact resistance of the structure are discussed.this part of the research results show that the combination of gradient design method can effectively improve the energy absorption capacity of the structure.The finite element model of three-dimensional honeycomb sandwich panel is constructed,and its failure behavior under local impact is simulated and analyzed,and the impact failure mode,punch contact force and energy absorption value of the sandwich panel are given.The effects of impact velocity and gradient arrangement mode on the energy absorption of sandwich panels are discussed,which promotes the practical application of negative Poisson’s ratio honeycomb sandwich panels.