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New damage model to simulate ballistic impact on concrete targets
Published in Günther Meschke, Bernhard Pichler, Jan G. Rots, Computational Modelling of Concrete Structures, 2018
L. Pereira, L.J. Sluys, J. Weerheijm
For obvious practical reasons, when studying ballistic impact, researchers focus primarily on the influences of the concrete grade/quality, target geometry and impact velocity on the penetration depth or residual velocity of the projectile. The experimental work by Beppu et al. (2008) goes a step further and, in addition to the typical analysis of the post mortem specimens to determine the perforation depth and size of crater and spalling area, high speed video cameras were used to record the evolution of cratering and spalling. These authors conducted a systematic study designed to investigate how the local failure process on plane concrete plates change with projectile velocity and target thickness, during ‘rigid’ impact. Single steel mushroom-like projectiles were fired against a series of 500 × 500 mm2 squared concrete plates with thicknesses ranging from 30 mm to 130 mm. Only impact normal to the plate surface was investigated, with velocities ranging between 200 m/s and 500 m/s. A set of the reported tests has been simulated for the numerical validation of the proposed model.
Energy absorption of the Kevlar®/PP hybrid composite: fabric to composite optimization
Published in The Journal of The Textile Institute, 2022
Mehrdad Hossein Alizadeh, Mehdi Kamali Dolatabadi, Saeed Shaikhzadeh Najar, Reza Eslami-Farsani
In the ballistic impact, the kinetic energy of the projectile is dissipated and absorbed by the target in several ways upon impact. The main energy-absorbing mechanisms during ballistic impact are as follows: kinetic energy absorbed by the moving cone that forms on the back of the target, shear plugs of the projectile in the target, energy absorbed due to the tensile failure of the primary yarns, energy absorbed due to the elastic deformation of the secondary yarns, energy absorbed due to cracks in the matrix and delamination and the frictional energy absorbed during penetration. The ballistic impact performance of composite laminates is dependent on the mechanical properties of the reinforcement/matrix and physical properties of the impacting projectile and the target. Mechanical properties of the target include the elastic modulus, tensile strength, fracture strain and laminate configuration. Projectile properties also include mass and shape. Thickness and size are the target parameters that can affect ballistic impact. A ballistic impact is generally a low mass and high-velocity impact caused by a propulsive source. The ballistic limit of a target is defined as the maximum velocity of a projectile at which complete perforation occurs with a zero exit velocity (Naik & Shrirao, 2004; Patil & Naik, 2018).
Influence of target dynamics and number of impacts on ballistic performance of 6061-T6 and 7075-T6 aluminum alloy targets
Published in Mechanics Based Design of Structures and Machines, 2022
Suresh Kumar Sundaram, Bharath A. G., Aravind B.
In general, the phenomenon “ballistics” deals with projectile impact and its effect on a target. Protection of military vehicles and soldiers against external high velocity projectile impact is one of the fundamental requirements as ballistic impact can cause penetration of the target by the projectile. High velocity impact caused by the projectile is generally considered as low mass and high velocity. The penetration of the projectile into the target causes several failure mechanisms such as, brittle fracture, ductile hole growth, and petaling etc., (Figure 1). Since “Terminal Ballistics” deals with the effect of projectile on its target, protection against external high velocity projectiles is one of the important requirements for the structural elements used in regions such as engine room, turret and ammunition room of the Defense vehicle. The penetration of tank armor by armor-piercing projectile is an important concern of terminal ballistics. The major cause of tank failure is due to impact loading caused by the projectile which penetrates through the tank sheet and causes tearing and thus it becomes mandatory to enhance the ballistic resistance of the targets against projectile impact.
Experimental and analytical studies of syntactic foam core composites for impact loading
Published in International Journal of Crashworthiness, 2022
Daniel Paul, Velmurugan R, N. K. Gupta
Modern defense, aerospace, and naval applications require lightweight materials that are also resistant against extreme loads. Impact from projectiles and debris is one such case. Composite materials are found to fulfill the above-mentioned requirements. The use of composite materials in naval applications is discussed in detail by Mouritz et al. [1]. Despite a few issues such as the difficulty in joining composites and the need for stringent performance requirements to resist underwater shock and impact loads, composites are replacing other materials in various applications. High-velocity impact by smaller projectiles is termed as ballistic impact. A number of studies have been performed on the analysis of ballistic impact on composites. Silva et al. [2] have studied the ballistic impact of projectiles resembling fragments on composite plates reinforced with Kevlar fibres. The V50 value is a measure of the ballistic limit, which is an important parameter under these impact conditions. It is the velocity at which the projectile has a 50% chance of penetrating the impacted sample completely. Velmurugan et al. [3] have used cylindrical projectiles with conical heads to study the impact of sandwich plates with polyurethane foams. The various modes by which the kinetic energy of the impacting projectile is absorbed by the target are quantitatively investigated.