| Ceramic materials are widely used in the field of armor protection because of their excellent physical and chemical properties such as high hardness,high specific strength and high stability.Due to the poor toughness and brittle fracture of ceramic materials,they are often used in the panel structure of composite armor.In order to solve the effect of heterogeneous interface stress wave on the strength of ceramic composite armor,the structural optimization of ceramic composite armor has become an important research direction of protective materials.In this paper,based on the honeycomb ceramic structure,mullite honeycomb ceramic material was filled with quartz sand and coated with polyurea to prepare ceramic matrix composites,and the impact resistance of the filled ceramic matrix composites was studied.Firstly,through the theoretical analysis of the failure mode of ceramic materials and the deformation mechanism of honeycomb structure,it is determined that the matrix of ceramic materials is honeycomb through-hole,the vertical plane is honeycomb ceramic structure facing the projectile,and the composite mode is honeycomb hole filled with quartz sand and sealed by polyurea coating material.In terms of mechanical properties,honeycomb ceramics have a very short plastic deformation stage,and the honeycomb structure aggravates the ceramic fragmentation under the impact response of projectile body,so it is difficult to bear the impact energy.However,the plasticity of the filler and coating materials in the ceramic matrix composites is high,which increases the structural strength of the target plate through the confinement effect.Secondly,the impact simulation and structure optimization of honeycomb ceramics are carried out by LS-DYNA software,and the influence of cell shape,honeycomb wall thickness,honeycomb hole diameter and impact point on the impact resistance of honeycomb ceramics under bullet impact is analyzed.Compared with the impact simulation process of ceramic matrix composites,the results show that the shape of honeycomb cells has little influence on the impact resistance,the material strength increases with the increase of honeycomb wall thickness,and the energy absorption density increases with the increase of honeycomb pore diameter.The energy absorption density of the ceramic matrix composite is 55.8% higher than that of the honeycomb ceramic when the thickness of the honeycomb is 1 mm and the diameter of the honeycomb hole is 2 mm.Finally,the penetration tests of honeycomb ceramics and ceramic matrix composites are carried out.The whole structure of honeycomb ceramic target is broken,which verifies the stress concentration problem of honeycomb ceramic in the theoretical and simulation models.The structure of ceramic matrix composite target plate is complete,and the debris morphology in the penetration hole proves that the composite material improves the toughness of honeycomb ceramic target plate,avoids the premature fragmentation of ceramic material,and improves the absorption efficiency of impact energy. |
