Ballistic Application of Coir Fiber Reinforced Epoxy Composite in Multilayered Armor

Abstract

Multilayered armor systems (MAS) composed of relatively lighter materials with capacity to provide personal ballistic protection are being extensively investigated and used in armor vests. A typical MAS to stand high impact energy 7.62 mm bullet has a front ceramic followed by an aramid fabric laminate, such as Kevlar™. Since both the army and municipal police personnel might need to wear an armor vest, a large number of vests needs to be supplied. In the case of Kevlar™, one of the most expensive MAS material with an expiration time of 5 years, the possibility of its replacement by an equally ballistic efficient low cost material and more durable could be a relevant economical advantage. Natural fibers composites have recently been investigated as possible alternatives for Kevlar™. In particular, the fiber extracted from the coconut fruit, known as coir fiber, normally disposed as waste, could be a low cost material for this purpose. Therefore, the present work investigated the possibility of using coir fiber mantle, with different volume fraction, reinforcing epoxy composites as MAS second layer. It was found that 30 vol% of coir fiber composite displayed similar ballistic performance as compared to Kevlar™ with substantial economical advantage.

Composites with Natural Fibers and Conventional Materials Applied in a Hard Armor: A Comparison

“…However, level IIIA ballistic vests, which protect against ammunition with an impact velocity lower than 450 m/s, such as 9 mm and .44 Magnum bullets, are often transformed into level III for protection against 7.62 mm bullets by placing inserts (armor plates) on the vest front, which was the objective of the present work. A comparison between the results obtained in previous works for the MASs with three layers [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 27 , 28 , 29 , 30 , 31 ] and the BFS depth of hard armor systems (without the Al alloy) tested in this work is shown in Figure 4 . All MASs presented in this figure have a composite plate with 30 vol % of natural fiber, which is the same as the volume fraction for the tested PALF composite.…”

“…These systems are specially designed with a front ceramic for protection against high-velocity (>800 m/s) ammunitions classified as level III [ 11 ], such as 7.62 mm caliber, mostly used by military armed forces. Although much weaker than aramid fiber, the investigated natural fiber polymer composites [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ], as an MAS second layer, display comparable ballistic performance to Kevlar with the same thickness. This performance is measured by the behind armor blunt trauma (indentation) caused in a clay witness, simulating a human body, that was placed behind the MAS target.…”

“…Although the use of natural fiber composites in ballistic armors has been reported in many papers [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ], most of the published work thus far involves a possible third layer in the MAS. This layer is an aluminum alloy, which compromises the armor vest weight.…”

Eficiência Balística De Sistemas De Blindagem Multicamada Com Compósitos De Epóxi Reforçados Com Tecido De Fique

“…Atualmente são utilizadasblindagens de um único material eblindagensmulticamadas, a aplicação depende do poder da munição. Um sistema de blindagem multicamadas (SBM) fornece proteção contra projéteis de alta velocidade de impacto, como o calibre 7,62 mm [1]. Sistema de blindagem de componente único baseado em aço, compósito ou outros sistemas não são muito eficazes para resistir à penetração do projétil [2].…”

Desempenho Do Compósito De Matriz Poliéster Reforçado Com Fibra De Fique Em Um Sistema De Blindagem Multicamada

“…5(b) mostra a capacidade da segunda camada compósita de tecido de 20 vol%, na MAS com uma frente cerâmica, para recolher fragmentos gerados a partir do impacto balístico. Esta capacidade não requer fibras mais fortes, mas mecanismos de incrustação mecânica, bem como atração de fragmentos pelas forças de Van der Waals e cargas estáticas na superfície da fibra, de compósitos sintéticos de Kevlar ™ ou de fibras naturais [28][29][30][31][32].…”