Ceramic Composite Armor Research Articles

Numerical simulation and experimental research on penetration of composite ceramic armor by rod projectile

The performance of composite ceramic armor penetrated by rod projectile was studied by both numerical simulation and experiment. The penetration and damage mechanisms of the projectile-armor after high-speed collision were also observed by high-speed photography. The experimental results showed that the ballistic performance of composite ceramic armor was highly affected by the density, hardness and toughness of bulletproof ceramic. The flow stress of the failed bulletproof ceramic is not only related to the pressure but also related to the strain rate. The phenomenological method based on Bodner-Partom ceramic model was introduced to derive the growth rate of damage. Numerical simulation results show good agreement with the experimental results.

Numerical simulation of ceramic composite armor subjected to ballistic impact

Armor systems made of ceramic and composite materials are widely used in ballistic applications to defeat armor piercing (AP) projectiles. Both the designers and users of body armor face interesting choices – how best to balance the competing requirements posed by weight, thickness and cost of the armor package for a particular threat level. A finite element model with a well developed material model is indispensible in understanding the various nuances of projectile–armor interaction and finding effective ways of developing lightweight solutions. In this research we use the explicit finite element analysis and explain how the models are built and the results verified. The Johnson–Holmquist material model in LS-DYNA is used to model the impact phenomenon in ceramic material. A user defined material model is developed to characterize the ductile backing made of ultra high molecular weight polyethylene (UHMWPE) material. An ad hoc design optimization is carried out to design a thin, light and cost-effective armor package. Laboratory testing of the prototype package shows that the finite element predictions of damage are excellent though the back face deformations are under predicted.

Study on the Ballistic Performance of Ceramic Composite Armor with Different Adhesive

Adhesive is an important part of ceramic-metal composite armor. In order to obtain excellent ballistic performance, some adhesive with a variety of content of nano-SiO2 was prepared, and mechanical properties and ballistic test were conducted. The results show that the pores in adhesive decrease the strength of the adhesive, and the fracture happens along with the pores. To add nano-SiO2 in adhesive can decrease the porosity and the scale of the pores. In the ballistic performance, the adhesive enhance the acoustic impedance, the greater acoustic impedance can increase the energy of transmission wave and decrease the energy of reflection wave, leading to that the ceramic is destroyed slightly. The targets with adhesive added in 20% nano-SiO2 express the best anti-bullet properties. There are so many big blocks left in targets and the height of back convex is only 2.36mm.

Functional graded material with nano-structured coating for protection

Ceramic composite armour that is use in bullet proof vest utilises a front layer of dense ceramic, typically backed by a second layer of metal. The weakest link of the material system is at the interface between the transition of the ceramics and metal. The use of functionally graded materials can help to reduce the dissimilarity at the interface, thereby providing high hardness of ceramics at the top surface with the combination of good ductility of the metals for the backing. Further enhancement was made with the application of the nano-structured coating that increases the surface hardness by 2-3 as compared to the dense ceramic tile. Laboratory scale experiments were being performed to exhibit the potential of this material in terms of physical and mechanical properties.

Functional Graded Material with Nano Coating for Protection

Ceramic composite armour in general utilises a front layer of dense ceramic, typically backed by a second layer of metal. Thereby creating a sharp interface that is the weakest link within the material system and would result in cracking of the ceramic prematurely and hence not able to provide the requisite protection. One promising possibility has been found is the use of functionally gradient materials as armour materials. In such materials, the high hardness of ceramics is combined with the ductility of metals. Laboratory scale experiments were being performed to exhibit the potential of this material in terms of physical and mechanical properties. A comparison was made with the current ceramic armour system and it was found that the new material system had better ballistic properties.

Penetration analysis of a projectile in ceramic composite armor

Abstract In this research an armor material with constant thickness has been studied. The armor consists of two layers: one is a boron carbide ceramic and the other is Kevlar 49 fiber composite material. By using Ansys/Lsdyna software, the ballistic limit velocity of this armor has been obtained and the Heterington equation (optimum thickness of layers) has been verified for constant thickness of the armor. In this research, mechanical properties of Kevlar 49 under different strain rates are utilized and showed that consideration of the strain rate is very important for the simulation of penetration process. Results from the model have confirmed the validity of the Chocron–Galvez analytical model. Moreover, the projectile velocity prediction, especially at high velocity, shows a good agreement with numerical simulations. Finally, normal and oblique impacts of projectile to armor have been simulated and compared. The results show that the ballistic limit velocity of armor increases under oblique impact conditions.

Lightweight ceramic composite armour system

The development of lightweight armour systems for ballistic protection is under continuing attention of the manufacturers and users. A new design of the composite armour systems has been developed and ballistically tested. A new armour system consists of a ceramic plate, an intermediate ceramic–polymer layer and a polymer fibre lining as a backing material. The proposed composite armour systems prepared with a use of specially selected compositions of the intermediate layer promoting the absorption of the kinetic energy of projectiles provide adequate ballistic protection to National Institute of Justice (NIJ) level III and level IV, and they successfully withstand multiple hits.

Numerical simulation of normal and oblique ballistic impact on ceramic composite armours

This paper presents three-dimensional finite element models that investigate the performance of ceramic–composite armours when subjected to normal and oblique impacts by 7.62 AP rounds. The finite element results are compared with experimental data from different sources both for normal and oblique impact, respectively. Simulation of the penetration processes as well as the evaluation of energy and stresses distributions within the impact zones highlight the difference between normal and oblique ballistic impact phenomena. The findings show that the distributions of global kinetic, internal and total energy versus time are similar for normal and oblique impact. However, the interlaminar stresses at the ceramic–composite interface and the forces at the projectile–ceramic interface for oblique impact are found to be smaller than those for normal impact. Finally, it is observed that the projectile erosion in oblique impact is slightly greater than that in normal impact.

The effect of obliquity on the ballistic performance of two component composite armours

Summary This paper examines the performance of composite armours when subjected to oblique impact. Experimental results are presented from a programme of trials on ceramic-aluminium targets using 7.62 mm ball ammunition. The results show that an inclined ceramic composite armour plate will perform better, on a thickness basis, than one arranged perpendicular to the line of impact. However, the degree of improvement thus obtained is much less than for steel armours. Moreover, it is shown that minimum weight protection to a vulnerable area, using ceramic composite armours, is achieved when the armour is perpendicular to the threat. The degree of thickness reduction which is obtained by angling ceramic composite armours is much less than for steel armours. A theoretical model of oblique impact is presented and shown to correlate well with the experimental results.

Numerical modelling of normal impact on ceramic composite armours

Summary In this paper, the penetration of ceramic targets backed by thin metallic plates when impacted by cylindrical projectiles is studied. To achieve this, a two-dimensional axisymmetric numerical analysis of the normal impact problem is performed. The macroscopic material behaviour in the zone of finely pulverized ceramic ahead of the penetrator is modelled by means of a constitutive model taking into account internal friction and volumetric expansion. The amount of comminution at the computational cells is evaluated through a damage evolution equation, and the yield stress is assumed to be a function of the hydrostatic pressure, internal friction and amount of comminution. For the metallic materials involved, an elasto-plastic behaviour with a rupture condition was considered. Moreover, an erosion condition was included as a limit situation when the ruptured material limits its role in the penetration process to purely inertial effects. In this way, a detailed picture of the penetration process of the target by the impacting projectile was obtained. Then, the results of the numerical analysis were compared with the experimental observations of the projectile-target interaction, previously made by Reijer by using a flash X-ray technique. Under certain conditions, remarkable agreement between computations and experiments is encountered, thus suggesting the adequacy of the main assumptions made in the numerical approach to the physical situation.

A simple one-dimensional approach to modelling ceramic composite armour defeat

This work develops a simple set of models for the perforation of ceramic composite armour, which highlight the essential physical processes and illustrate approximately the dependency of ballistic resistance on physical properties and impact parameters. The major features of ceramic composite armour failure (viz. fracture conoid formation, dishing failure of thin backing plates, perforation of thick packing plates, and projectile erosion) are combined with a lumping of masses to treat material acceleration to produce simple models which allow computations on ceramic targets with both thin and thick metallic backings. Calculations are compared with a broad range of empirical data and are also used to discuss aspects of the interaction of penetrators with ceramic composite armours. The goos correlation of models with experiment demonstrates the usefulness of the present approach for studying ceramic composite armour defeat.