| In order to make the armor achieve light weight and good bullet-proof effect,this paper innovatively proposes a negative Poisson’s ratio metal/ceramic composite structure material.A simple,easy-to-manufacture and easy-to-assemble concave honeycomb structure is selected as the research object,and the influence of the angle parameter θ,size parameter l and thickness parameter t of the honeycomb cell on the Poisson’s ratio and energy absorption of the honeycomb structure is studied.Then study the compressive performance of the unit cell metal/ceramic composite structure under quasi-static compression and its impact resistance under dynamic impact.Finally,the bullet penetration resistance of the metal/ceramic multi-cell lattice composite structure is studied.The main research content and conclusions of this paper are as follows:1.ABAQUS was used to simulate and study the influence of the angle parameterθ,size parameter l and thickness parameter t of the honeycomb cell on the Poisson’s ratio and energy absorption of the overall structure.Then,the correctness of the simulation is verified through compression experiments,and the reason for the compression resistance of the negative Poisson’s ratio structure is analyzed.The research results show that when the angle is negative,the honeycomb structure has a negative Poisson’s ratio,and its energy absorption is larger than that of the honeycomb structure with a positive angle.The smaller the cell width and the larger the wall thickness,the more energy absorbed by the honeycomb structure.The angle parameter has the greatest influence on the Poisson’s ratio of the honeycomb structure,and the wall thickness parameter has the greatest influence on the energy absorption.The concave honeycomb structure shrinks both longitudinally and laterally when it is compressed,and the internal structure becomes tighter than ordinary honeycombs and has better compression resistance.2.Based on the Mohr strength theory combined with the basic principles of strong-toughness coupling,a negative Poisson’s ratio metal/ceramic composite material is proposed.The universal testing machine is used to perform quasi-static compression on two composite cells with angles of-30° and 30° to study the compression resistance of the unit cell metal/ceramic composite structure.The experimental results show that the metal/ceramic composite cell with an angle of-30°can withstand greater pressure during the compression process,and the entire cell structure is less deformed.Only longitudinal cracks appear in the internal ceramics,and the composite cell has better compression resistance.The peak pressure of the composite cell at an angle of 30° is relatively small.Because the internal ceramic is concentrated and bursts instantaneously,the composite cell has poor compressive performance.3.The impact experiments of two kinds of composite cell structures with angles of-30° and 30° were carried out with Hopkinson pressure bar at different speeds respectively to study the impact resistance of the unit cell metal/ceramic composite structures.By comparison,it is found that the composite structure with an angle of-30° gathers more toward the center after impact,and the structure is more compact and bears higher load.However,when the 30° metal/ceramic composite cell is hit by the rod,the gap between the ceramic and the metal becomes larger and the ceramic cracks appear,and the impact load of the structure is also lower.4.ABAQUS was used to simulate the penetration angle of-30° and 30°metal/ceramic multi-cell composite structure and common metal target plate,the anti-penetration performance of lattice metal/ceramic composite structure is studied.The results show that the acceleration of the bullet penetrates-30° metal/ceramic composite material is higher,and the speed drops faster.It shows that the-30°composite structure has better anti-penetration performance,which can meet the protection requirements of mechanical metamaterials with light weight and good penetration resistance. |
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