Analysis Of Energy Absorption And Compression Characteristics In Honeycomb Structures With Random Defect And Gradient Wall Thickness

It is found that the metal honeycomb structure has the advantages of lightweight,high strength,sound insulation and energy absorption.Especially the good cushioning performance,and energy absorption effect of the aluminum honeycomb structure in the compression process,it is widely used in industrial production packaging,shock absorption,internal filling,aerospace,and military engineering.Due to the influence of various factors such as the production process,it is inevitable for metal honeycomb material to produce uneven random defects and uneven thickness in the production process.In order to understand the influence of random defects and gradient wall thickness on the mechanical properties of honeycomb structure materials,this paper takes hexagonal aluminum honeycomb structure as the research object,and applies different degrees of random defects and gradient wall thickness to study the influence of random defects and gradient wall thickness on the dynamic compression and cushioning energy absorption properties of hexagonal honeycomb structure under different impact loads,and compares with uniform honeycomb structure.ABAQUS finite element software is used for numerical simulation analysis.According to the results of numerical simulation analysis,the following conclusions are drawn :1.The stamping process of homogeneous hexagonal honeycomb can be divided into three parts: elastic deformation stage at the initial stage of loading,plastic stage at the middle stage of loading and failure stage at the end of loading.From the stress-strain point of view,the honeycomb material first reaches a stress peak,then enters the platform stress stage,and finally enters the stress surge section,the initial stress peak increases with the increase of impact load.From the energy absorption point of view,the energy absorption efficiency amplitude of unit mass honeycomb material is positively correlated with impact load.2.That the non-uniform hexagonal honeycomb single gradient wall thickness can effectively improve the stamping deformation characteristics of honeycomb materials,and the positive and negative gradient distribution can effectively use the material strength and save materials;random defects with different defect rates have a positive effect on improving the deformation band accumulation of honeycomb materials,which can reduce the initial stress peak of honeycomb materials,and effectively prevent the local failure caused by excessive deformation accumulation.However,with the increase of defect rate,the impact strength of the material decreases.3.When the gradient wall thickness and random defects are applied,the random combination of a small number of random defects and gradient wall thickness can not only make full use of the brightness of honeycomb material to actively improve the deformation characteristics,but also alleviate the problem of excessive accumulation of deformation band and local damage.When the defect rate is too high,it not only has no positive effect on the energy absorption of honeycomb material but also makes the deformation band disperse excessively and weakens the honeycomb material under the same condition,the platform stress of gradient thickness honeycomb material with random defects is negatively related to the impact load.