Study On Mechanical Behavior Of Metal Nonlinear Deformation Of Gradient Aluminum Honeycomb

Inspiration for the bee hive honeycomb structure design because of its light weight,high strength,low cost and excellent impact resistance and the energy absorption characteristic has been appli ed in many engineering practice.At the same time,with the development of economy and the progress of science and technology,the efficiency of the transportation and pervasive far off at any time,the traditional cellular structure already could not satisfy the present transportation due to the collision accident to absorb a large number of kinetic energy in order to ensure the safety of passengers,therefore,greater energy absorption characteristics of honeycomb structure become the research focus of researchers and but for different segmentation study of hierarchical cellular in cellular specification is less,Is all about the existing achievements have obviously different specifications of cellular structure series,the structure of the multilayer cellular same specifications as the primary research,rarely with linear gradient rule and a layer for level 1 of the cellular studies,therefore system series gradient,the mechanical properties of honeycomb structure study and explore the series gradient preparation of honeycomb structure has an important theoretical and engineering significance.The linear series gradient theory was designed,and the topolo gical model of series gradient honeycomb structure with one laye r as one level was established.At the same time,the preparation method of series gradient honeycomb structure was studied,and the actual honeycomb structure was obtained.On this basis,static and quasi-static compression experiments were used to detect the mechanical properties of gradient honeycomb materials with different topological structures,and the finite element technology was used to simulate the deformation mode,platform stress an d energy absorption.The results showed that the numerical simulation results were in good agreement with the experimental results.The finite element analysis of series-gradient honeycomb shows that the deformation mode of series-gradient honeycomb structure is obviously affected by the compression rate.In the quasi-static compression process,the deformation mode of the series gradient honeycomb structure is significantly different from that of the uniform honeycomb structure,and with the gradient rate(λ)changing,the deformation mode is gradually similar to that of the uniform honeycomb structure.In the dynamic compression process,the deformation mode gradually converges with the increase of compression speed.The positive and negative gradient rate(λ)also have obvious influence on the deformation mode and mechanical properties of the series gradient honeycomb structure during compression.At the same time,the stress and the gradient of honeycomb structure platform has close relation with the comp ression speed and compression speed,the greater the cellul ar structure of the platform is the greater the stress values and when λ=-0.0088 in the early stage of the equivalent strain platform stress at low speed dynamic strengthening effect is significant.The series is gradient series energy absorption properties of honeycomb structure is higher than the negative gradient honeycomb structure,but a series of gradient and no obvious to improve than the effect of the energy absorption(SEA).A series gradient honeycomb structure with low speed dynamic strengthening was selected to prepare the sample and the quasi-static compression test and finite element simulation were carried out.The gradient ratio(λ)has an obvious effect on the load distribution of honeycomb structure,and the stress distribution of uniform honeycomb structure is more uniform at the same time,At the same speed,the deformation mode of the honeycomb structure wi th series gradient is similar to that of the uniform honeycomb structure,but the stress and energy absorption of the platform are lower than that of the uniform honeycomb structure with compression in the Y direction.The stress fluctuation of the series gradient honeycomb structure is obviously reduced and the plastic deformation energy is twice as much as that of the uniform honeycomb under the high speed dynamic compression in the X direction.This shows that the gradient honeycomb material has obvious anisotropic mechanical behavior and energy absorption characteristics are closely related to impact velocity and force direction.