A Research On Impact Dynamic Response Of Layered Functionally Gradient Honeycomb

Compared with the traditional honeycomb structure,honeycomb porous structure with functional gradient can reduce initial stress peak,improve impact resistance and energy absorption.With the discovery and research of materials with negative poisson's ratio,the functionally gradient honeycomb structure with negative poisson's ratio has attracted widespread attention.Therefore,the finite element software ABAQUS is used to compute the in-plane impact dynamic performance of hexagonal and negative poisson's ratio honeycomb structures with different structure types under two gradient modes.The main research contents are as follows:1.The impact dynamics of uniform hexagonal and concave hexagonal honeycomb structures are verified from three aspects of structural deformation mode,impact dynamic response and energy absorption rate.At the same time,the dynamic response and energy absorption of two honeycomb structures with different proportions of loss are analyzed according to the deformation modes of two honeycomb structures.Compared with previous studies,the accuracy of the model is verified.2.By changing the vertical height of each layer cell structure,functional gradient material theory was used to make it show asymmetric or symmetrical layered height gradient hexagon and concave hexagon honeycomb structure.At the same time,The dynamic response and energy absorption of honeycomb structures with different proportions of loss are studied according to the deformation model of honeycomb structures with height gradient.And compared with the corresponding uniform honeycomb structure,the dynamic response and energy absorption of honeycomb structures with stratified height gradient are discussed.3.By changing the number of cells in each layer,symmetrical and asymmetric hexagons and negative poisson's ratio honeycomb structures with stratified density gradient were constructed,and their dynamic behaviors under various impacts were analyzed.Then,according to the deformation model of density gradient honeycomb structure,the dynamic response and energy absorption efficiency of honeycomb structure under different proportion cell loss are discussed.Finally,compared with the previous studies,the impact dynamics behavior of honeycomb structures with stratified density gradient is discussed from the aspects of stress-strain curve and energy absorption.The results show that different gradient mode,structure type and impact velocity will affect the dynamic response of these structures.When the structure type and the gradient change mode are in the same,the greater the impact velocity is,the greater the platform stress of the structure will be,and the higher the energy absorption rate will be.But the functionally gradient negative poisson's ratio honeycomb material has higher impact resistance.If the mode of gradient can be reasonably selected,it can effectively reduce the initial stress peak,protect the structure and improve the material's energy absorption capacity.