The Energy Absorption Characteristics And Simulation Analysis Of Quasi-square Honeycomb Sandwich Structures Filled With Foam

With the continuous promotion and application of sandwich structure materials in high weight and high energy consumption equipment in automobile,aerospace,machinery and other fields,nowadays only sandwich structure cannot meet all requirements of engineering design,so new composite materials with higher energy absorption and higher strength need to be developed.Sandwich layer is an important part of sandwich structure.The overall bearing capacity and energy absorption capacity of sandwich structure will be improved after filling foam.This paper takes the quadrate honeycomb sandwich layer as the research object,and studies the dynamic energy absorption characteristics of the quadrate honeycomb sandwich structure with equivalent wall thickness by combining theoretical analysis,numerical simulation and experiment.The main research contents are as follows:(1)The equivalent elastic parameters of the hexagonal honeycomb sandwich structure with the equal wall thickness were derived by the improved Gibson formula and the energy method,and the formula for calculating the equivalent elastic parameters of the quasi-square honeycomb sandwich structure with the equal wall thickness was obtained by taking advantage of the characteristics of the special hexagon honeycomb.The critical zero value of poisson's ratio between positive poisson's ratio and negative poisson's ratio is analyzed with finite element method.The honeycomb specimen with equal wall thickness was fabricated and compressed in plane to verify the theoretical formula.(2)It analyze the dynamic response,deformation mode and energy absorption capacity of the quasi-square honeycomb sandwich filled with polyurethane foam under impact loads in different velocity surfaces by numerical simulation.And the impact characteristics were compared with those of the unfilled honeycomb sandwich.The results shows that quasi-square honeycomb sandwich layer filled with nothing is more easily by crushing,after filling plastic foam,quasi-square honeycomb sandwich in-plane impact load are prone to buckling failure and the energy absorption capacity and impact velocity is not too big correlation,but the specific energy absorption is relatively not fill class square honeycomb sandwich got up,and energy absorption process is relatively stable.(3)It analyze the dynamic response,deformation mode and energy absorption capacity of quasi-square honeycomb sandwich filled with foam under the out-of-plane impact load at different speeds from the perspective of external impact of quasi-square honeycomb sandwich.And compare it with the impact characteristics outside the quasi-square honeycomb sandwich without filling.The results indicate that the energy absorption ability of quasi-square filled with foam is increased significantly,with the increase of impact velocity and the deformation modes of its apparent inertia effect,but its peak stress also increases accordingly,and quasi-square honeycomb sandwich deformation pattern did not produce obvious change with the increase of impact velocity.At the same time,the evaluation index function-specific energy absorption and energy absorption efficiency-of impact energy absorption characteristics outside the quasi-square honeycomb sandwich surface is established with simulation data.The research results of this paper provide new ideas for the innovative design of lightweight materials and structures,and have important theoretical research significance and application value.