Papers by Keyword: Ballistic Limit

Abstract: In this paper, the post ballistic impact behaviour of kevlar-glass fibre hybrid composite laminates was investigated against 9×19 mm projectile. Eight different types of composite laminates with different ratios of kevlar woven fibre to glass fibre were fabricated using hand lay-up with epoxy matrix. Ballistic behaviour like ballistic Limit (V₅₀), energy absorption, specific energy absorption and Back Face Signature (BFS) were studied after bullet impact. The results indicated that as the Percentage of glass fibre is increased there was a linear increment in the ballistic behaviour. Addition of 16% kevlar fabric, composite sample meets the performance requirement of NIJ0101.06 Level III-A. Since the maximum specific energy absorption was observed in Pure Kevlar samples and the adding of glass fibre increases the weight and Areal Density of the sample, further investigations need to be carried out to utilize the potential of glass fibre for ballistic applications.

Abstract: One of the urgent tasks of the development of new protective structures is to improve the ballistic performance of thermoplastic composites reinforced with synthetic high-strength fibres. Hybrid composites based on various types of fibres or fabrics with different weaving could be a possible solution to this problem. This paper presents the results of computational and experimental studies of hybrid composites based on aramid fabrics with satin and plain weave structures. Numerical modelling based on the reduced ply-level approach was used for the design of hybrid composites. The results obtained during calculations were in good agreement with validation experiments.

Abstract: This paper explains the utilisation of finite element model to analyse the ballistic limit of aluminium alloy 7075-T6 impacted by 8.33 g with 12.5 mm radius rigid spherical projectiles. This numerical study was compared with the results obtained experimentally. During impact, the targets were subjected to either non- or uniaxial- pretension and the projectile travelled horizontally to the target. It was observed that pretensioned targets were more vulnerable, which reduced the ballistic limit. The existence of harmful failures owing to pretension impact was ascertained and compared with the non-pretension targets.

Abstract: This paper presents the ballistic impact study for the non-filled aluminum tank. The objective was to determine the ballistic limit for front tank wall and rear tank wall. The tank was impacted with fragment simulating projectile (FSP) with various velocities range from 239 m/s up to 556 m/s. The aluminum tank was 3 mm thick, 150 mm wide and 750 mm long. The ends of tank were closed with two Polymethyl methacrylate (PMMA) windows which fixed to the tank with four steel bars. The test was conducted at the Science and Technology Research Institute for Defense (STRIDE) Batu Arang, Selangor. The results showed that the ballistic limit for the front tank wall and rear tank wall was 257.7 m/s and 481 m/s, respectively.

Abstract: Body armor is a material to protect body from injury of various kind of high speed projectile impact velocity in combat or other dangerous situation. Researchers were found to actively research and exploring new body armor technology due to the invention of new firearms. Furthermore, they were also competing in developing ballistic panel which is lighter in weight, more flexible and comfort in use, cheaper in cost and manufacturability. This paper reviews the body armor commercial and current development materials, structure and construction techniques involved and related works on enhancing ballistic energy absorption.

Abstract: The bending toughness, strength retention, resistance to damage and bending stiffness of glass fiber mat, laminar composites under high strain rate impact loading conditions was studied. One of the main disadvantages of laminar composite materials is their poor interlaminar shear strength. Recent work has demonstrated a method of Z-direction reinforcement of these composites using electrostatic flocking techniques improve delamination resistance and fracture toughness without degrading the composites tensile strength or other in-plane properties when loaded quasi-statically. The Z-direction reinforcement is accomplished by electrostatically flocking short fibers perpendicular to and between the composite ply layers. In this study, composite samples were prepared using the flocking method in two fabrication modes by the; so-called Z-Axis wet and Z-Axis dry procedures. In this work, Z-direction reinforced composite panels (including a non reinforced control) that were previously projectile impact damaged were tested using established mechanical testing procedures. Damage areas were quantified and compared using image processing techniques. Three point bending tests were also conducted on these projectile impact damaged panels to determine and compare their bending toughness, strength retention and modulus. The results show that Z-Axis reinforcement by the flocking technique improves the overall mechanical strength and stiffness properties of glass fiber mat laminar composites. For example, Z-Axis reinforced projectile damaged and not damaged glass fiber mat composite laminates are found to have flexural strengths 9% to 15% higher and a flexural modulus (stiffness) 22% to 26% higher than comparable (not Z-Axis flock reinforced) glass fiber mat samples.

Abstract: Experimental results on the ballistic limits and failure mechanisms that lead to perforation in aluminum alloy target plates of 1-6 mm thickness by solid spherical projectile are presented. The projectile was launched between velocities of 150 m/s to 700 m/s by using the 10mm smooth bore gas gun. In this study, the attention was focused on the peculiarities of penetration process when the impact point approaches closely to the free or firmly fixed edge of the plate. The results were compared with the case of central impact and with others under changing the boundary condition, thickness and the target material properties.