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Failure Analysis
Published in David W. Richerson, William E. Lee, Modern Ceramic Engineering, 2018
David W. Richerson, William E. Lee
The ballistic testing of projectiles (bullets, rockets, etc.) is important when developing personnel and vehicle protection systems. Bullet-proof personnel vests are often monolithic alumina, while layered structures are used for vehicular protection with one layer being ceramic (often B4C) whose function is to deflect the energy perpendicular to the projectile direction of entry. Composite armor systems are used in ground vehicles, helicopters, ships, and mobile containers to protect against direct fire, mortar and artillery shrapnel, and landmines. The examination of impact failure has been key to the development of such systems, but the important ceramic mechanical properties for good ballistic protection are a matter of ongoing debate.23
Personal Protective Equipment (PPE) and Decontamination for Terrorist Agents
Published in Robert A. Burke, Counter-Terrorism for Emergency Responders, 2017
Siegel predicts that some of the most profound advances will be made in protective and high-visibility apparel. These enhancements will be derived from instrumented, lightweight, responsive textiles that use tougher, wear-resistant polymers that also benefit from embedded, ceramic–composite armor. Like future hand and foot protection, these garments will have embedded warning, thermal management, and first-aid systems. High- or modulated-visibility (tunable) textiles powered by lightweight, flexible batteries embedded in the fabric will enable manufacturers to produce garments that are visible day or night at any level of light. And when the need arises, these items will be equipped with electronic communications systems with interactive displays and remote monitoring of worker conditions. In a real sense, the future of worker protection looks very bright. But how far away are these PPE advances? While some may not be available until ISEA's 100th anniversary, others could be just around the corner. A show of hands at the “Protection 2033” symposium indicated that a number of ISEA member companies already are working to apply some of these miraculous new technologies to their products. Stay tuned.
Ballistic performance of composite armor with dual layer piecewise ceramic tiles under sequential impact of two projectiles
Published in Mechanics of Advanced Materials and Structures, 2022
Lihong Yang, Zongbing Chen, Yalun Dong, Fan Zi, Jinshui Yang, Linzhi Wu
Lightweight composite armors composed of different materials can provide the high ballistic protection level for military vehicle, aircrafts, and warship, etc. Some lightweight materials, such as ceramic[1, 2], fiber reinforced composites[3, 4], graphene [5], and others have attracted wide attention in the field of composite armor design due to their low density but excellent ballistic performance. The ceramic can play a leading role in the ballistic resistance of a composite armor owing to their high stiffness and hardness [6]. When a projectile with the high kinetic energy impacts on a ceramic plate, the shattered zone formed in the ceramic plate can absorb the partial kinetic energy of the projectile. Furthermore, the ceramic fragments formed during impact can also dissipate a large amount of kinetic energy of the projectile by eroding or blunting the projectile. Many researchers [7–11] focused on the ballistic performance of the composite armor fabricated by ceramic materials. Compared to single phase material, the composites materials provide the potential to combine the best distinctive physical and mechanical properties of their constituents, and thus, they can offer advanced multifunctionalities. The ballistic performance of fiber reinforced composite materials is a major concern due to its excellent characteristics (such as high tensile strength, high modulus, and low density) and its complicated failure mechanisms, including matrix cracking, interlayer delamination, fiber-matrix interfacial deboning, and fiber breakage [12]. The layered armor systems, such as composite armor composed of a ceramic face plate and a fiber reinforced composite back plate, have been increasingly developed and applied in recent years [13, 14]. The fiber reinforced composite, as a good backing material of armors, plays a main role in absorbing the kinetic energy of projectile and catching the ceramic fragments and projectile fragments. More attention was paid recently to the ballistic performance of various fiber-reinforced composite materials, such as E-glass fiber [4, 15], Kevlar fiber [16], carbon fiber [12], ultra-high molecular weight polyethylene fiber (UHMWPE) [17], and some natural fibers [18, 19].
Research on anti-penetration performance of composite armor of steel/composite materials
Published in Mechanics of Advanced Materials and Structures, 2022
Yalun Dong, Fan Zi, Lihong Yang, Jing Lu, Ziqi Jin, Linzhi Wu
In this paper, the anti-penetration performance of the composite armor composed of steel, Kevlar fiber reinforced composite and UHMWPE fiber reinforced composite was systematically analyzed. A large number of simulations were carried out to discuss the velocities of the projectile, energy absorption and failure modes of the composite armor. The main conclusions are as follows:The composite armor composed of steel and fiber reinforced composites has a better anti-penetration performance when the steel plate is placed in the front of the composites plate. As the front plate, the composite undergoes shear failure, and as the back plate, the interlayer delamination and tensile failure of the fibers occur. With the increase in the thickness of Kevlar, the specific energy absorption of the armor will reduce while the anti-penetration performance will be enhanced.The configuration with steel, Kevlar and UHMWPE on the first, second and third layers of the composite armor have the optimal anti-penetration performance since the excellent tensile properties of UHMWPE can give more contribution to the anti-penetration of composite armor when UHMWPE is used as the back plate of the armor.The ball-headed projectile has a better penetration ability than the flat-headed projectile of the same weight and diameter when penetrating the Steel/Kevlar composite armor. With the increase in the incident angle of the oblique impact, the penetration ability of the flat-headed projectile decreases due to the reduction of the normal velocity component of the projectile in the process of the oblique incidence.The total energy absorption of the composite armors increases with the increase in the impact velocity of the projectile, however, the total energy absorption of the armor of different configurations becomes similar. The effect of the armor configuration on the anti-penetration decreases with the increase in the impact velocity of the projectile.