Numerical Simulation Study On Anti-Penetration Performance Of SiC/UHMWPE Composite Armor

With the continuous progress of modern military technology and the continuous update of lethal weapons and equipment,new protective technologies and materials have emerged at the historic moment.The ceramic/fiber composite armor has become an important research direction in the current armor protection field.Silicon carbide(SiC)ceramics and ultra-high molecular weight polyethylene(UHMWPE)fiber reinforced composites have been widely studied and applied in the field of armor protection due to their characteristics of low density,high strength and excellent impact resistance.They are often used as the panels and backplates of composite armor.However,there are few systematic reports on the effect of interlayer bonding of fiber composite backplate on the anti-penetration performance of SiC/UHMWPE composite armor.In addition,the performance of composite armor is not only dependent on the material properties,but also related to the structure.Therefore,under certain conditions,it has practical significance for optimizing the design of SiC/UHMWPE composite armor and developing composite armors with higher performance to study the effect of interlayer bonding of fiber composite backplate and thickness configuration of different materials on the anti-penetration performance of composite armor.In this paper,the ballistic penetration test of SiC/UHMWPE composite armor against 7.62 mm armor-piercing incentov cocktails was carried out,and a series of test results about armor penetration and backface signature were obtained.Then,according to the actual situation of the test,the numerical simulation analysis method was used to establish the ballistic penetration model of SiC/UHMWPE composite armor against 7.62mm armor-piercing firebombs.The finite element analysis program MPP LS-DYNA was used to solve the above model,and the post-processing software LS-PREPOST was used to extract the numerical simulation results.The results of anti-penetration ballistic tests of a large number of composite armours are compared with the results of numerical simulation.The error of the backface signature is within the acceptable range of 5～6%.The results proved the feasibility of the numerical simulation analysis method and the reliability of the finite element model,which provided support for the subsequent numerical simulation research.Secondly,on the basis of the above finite element verification model,the bonding between materials is simulated by TIEBREAK contact which considers the layered failure and evolutionary of normal(MODE I),tangential(MODE II)and mixed modes.A series of finite element models of SiC/UHMWPE composite armor with different interlayer bonding property of the backplate of UHMWPE composite were established by modifying the bonding properties of normal fracture stress,tangential fracture stress,normal fracture toughness and tangential fracture toughness.Based on the simulation results,the effects of interlayer bonding property of SiC/UHMWPE composite armor on ballistic limiting velocity,energy absorption and damage mode of composite armor were discussed.The results show that the ballistic limiting velocity of SiC/UHMWPE composite armor decreases from 955 m/s to 821 m/s with the improvement of interlayer bonding property of the composite backplate.When the composite armor was not penetrated,the backface signature of the composite backplate reduced from 23.9 mm to 20.5 mm,and the time required for projectile velocity to zero reduced from 0.1586 ms to0.1389 ms.As the bonding property weakens,the backplate of the composite becomes more obvious in stratification,and more composite materials deform and fail in the way of stretching,absorbing more kinetic energy of the projectile.Finally,based on the established finite element verification model,a series of new composite armor finite element models with different thickness configurations of ceramic panel and composite backplate were established by modifying the geometric model size under the condition of constant surface density(41.85 kg/m~2)and total thickness(20 mm).Based on the simulation results,the performance difference of SiC/UHMWPE composite armor with different thickness configurations of ceramic panel and composite backplate was discussed.The results show that the ballistic limit velocity of composite armor model reaches 955 m/s and the anti-penetration performance of SiC/UHMWPE composite armor reaches the best when the thickness ratio of SiC ceramic plate to UHMWPE composite backplate is 1:1 under two cases of constant surface density and total thickness of SiC/UHMWPE composite armor.