Study On Impact Resistance Of Silicon Carbide And Ceramic Composite Armor

One of the development trends of armor protection technology in the future is lightweight,which can improve the protection efficiency of the protective structure while reducing the weight of the armor and improve the possibility of avoiding strikes.Compared with alumina ceramics,silicon carbide ceramics have better mechanical properties and lower density,and have broad application prospects in industrial production,military construction,aerospace and other fields.In this paper,the dynamic mechanical behavior of Si C composite armor is discussed through the Split Hopkinson Pressure Bar（SHPB）device,and the impact resistance of Si C composite armor is analyzed systematically by using numerical simulation software,and the mechanism of its impact resistance is revealed.The main work is as follows:（1）Quasi-static and dynamic uniaxial compression experiments were carried out on Si C ceramics,and it was proved that the strain rate-strength relationship of Si C ceramics is still compound Famesh function relationship.The critical strain rate is500^-1,and the characteristic strain rate is 3000^-1.Starting from the principle of crack propagation,and through the ceramic damage produced by the SEM experiment of debris image observation,in the macro and micro angle to explain the cause of silicon carbide strain rate effect,and puts forward the material porosity and powder shape differences may be a silicon carbide ceramic strain rate sensitivity is lower than the main cause of alumina ceramics.（2）The energy balance approach was used to analyze the penetration of cylindrical projectiles into ceramic-metal hybrid structures for the perforation of ceramic-faced light armors subjected to impact by flat-ended projectiles at normal incidence.An improved Florence model for ballistic limit velocity（BLV）prediction of double and three-ply ceramic/metal composite armor is presented.Various equations are obtained and compared with available experiments and numerical simulation results.Compared with Florence’s model,the accuracy of the new model is improved by about 20%.Different from the original model,the new model is suitable for the prediction of ballistic limit velocity of sandwich plate structure,and the new model takes bullet mass loss into account.Therefore,the new model still maintains high accuracy at high velocity penetration,and the error is less than 1%at high speed loading.（3）LS-DYNA numerical simulation software was used to establish a numerical model of armo-piercing projectile hitting ceramic armor,and the comparison between numerical simulation results and experimental data proved the accuracy of simulation results.Based on the simulation results,a numerical model of monolayer encapsulated ceramic composite structure was established,and the influence of the shape of ceramic partition on its impact resistance is systematically compared.It was found that the shape of hexagonal ceramic was better than that of quadrilateral.Due to the natural defects in the joints of partialized ceramics,a double-clad ceramic composite armor structure was established by using the obtained conclusions and considering the restraint effect and stratification effect of ceramic armor.The numerical analysis showed that the protection ability of the new model at the defects was increased by 14.8%compared with the original.