The Effect of Thickness on Aramid Fabric Laminates Subjected to 7.62 MM Ammunition Ballistic Impact

Abstract

Due to increasing improvement of weaponry and ammunition, attention is being given to the development of new materials that could more effectively resist to ballistic impact. In order to stop high energy bullets, with speed above 800 m/s, a high strength material is necessary. However, if just one material is used, then a relatively thick piece is required, which might affect negatively the wearer mobility. The objective of this work is to investigate the effect of thickness on the ballistic behavior of aramid fabric laminates, Kevlar ® , hit by high energy bullet. The purpose is to find the minimum thickness to avoid perforation. Ballistic tests using conventional 7.62 mm ammunition were performed according to standard procedures. The macro and microscopic aspects of the target specimens were evaluated. The results showed a change in the ballistic behavior of the laminates as their thickness increased. It was found that until the laminate was able to capture the bullet, 96 layers (~50 mm) were required. This is significantly higher than the necessary thickness for a multilayered armor to stop the same 7.62 mm bullet.

Otimização De Sistema De Blindagem Multicamadas Usando Técnicas Estatísticas De Box-Behnken Design E Análise De Regressão Múltipla

“…Este valor de c2 foi devido à interação já mencionada com a camada de alumínio. A Tabela 5 mostra também uma comparação do SBM com um laminado de tecido de aramida estudado em um trabalho anterior [26]. Embora o tecido de aramida seja ligeiramente mais leve do que o SBM otimizado, sua espessura de 50 mm para parar os 7,62 mm pode ser impraticável para aplicações de blindagem pessoal [26].…”

“…A Tabela 5 mostra também uma comparação do SBM com um laminado de tecido de aramida estudado em um trabalho anterior [26]. Embora o tecido de aramida seja ligeiramente mais leve do que o SBM otimizado, sua espessura de 50 mm para parar os 7,62 mm pode ser impraticável para aplicações de blindagem pessoal [26]. É importante notar, no entanto, que os resultados da otimização da espessura devem ser utilizados com cautela, pois o modelo BBD-MRA descreve a influência das camadas no comportamento SBM dentro do intervalo estudado, que envolve a espessura mínima cerâmica e do compósito de 8,5 e 6,5 mm, respectivamente, e alumínio com espessura máxima de 7 mm.…”

“…Espessura otimizada do SBM por dois métodos diferentes e comparação com laminados de tecido de aramida de um trabalho anterior[26].…”

Synthesis and modification of poly (p‐phenylene terephthalamide) for production of light‐weight hybrid composite armors reinforced with polymer composite nanofiber mats

“…Therefore, the optimum design of an armor system should incorporate two contrary features: efficient ballistic protection and mobility. 4,5 Metals or alloys such as steel can be employed to provide the required ballistic protection with a relatively low cost, but the resultant heavy and inflexible armor structure leads to reduced mobility of the vehicles and the military personnel. In order to meet the rising standards in many military applications and the increasing demand for weight saving and fuel efficiency, studies on the light-weight armor design have focused on the design of high-performance fiber-reinforced composite armors.…”

“…In order to meet the rising standards in many military applications and the increasing demand for weight saving and fuel efficiency, studies on the light-weight armor design have focused on the design of high-performance fiber-reinforced composite armors. 4,6,7 Among the high-performance polymer fibers, aramid fibers such as PPTA and their composites can meet these demands successfully as a consequence of their low density and excellent performance in terms of tensile strength, toughness, roughness, corrosion resistance, chemical resistance, and thermal stability. [8][9][10][11] The tensile strength of PPTA fiber is over five times that of steel wire on an equal weight basis and maintains its mechanical properties at very high temperatures as an excellent heat and flame resistant.…”