Ballistic Performance of Multi-layered Fabric Composite Plates Impacted by Different 7.62mm Calibre Projectiles

Abstract

At present, the use of refined numerical simulation is gaining more and more importance, especially in extreme load cases where large experimental test programmes are not feasible. A validated numerical methodology can be exploited to investigate critical behaviour as a "virtual test". According to this premise, a numerical investigation is presented in this work to study the ballistic resistance of Kevlar29-Epoxy fabric plates subjected to impacts of small calibre projectiles, armour piercing (AP), ball type, and a blunt shaped projectile (BSP), all with a 7.62 mm diameter. The numerical models were developed using the explicit finite element code LS -DYNA. The composite plate is 5 mm thick, made up of 12 layers. The fabric is impregnated in Epoxy matrix, to guarantee both structural and ballistic resistance, and is a 2D plain-weave. The mechanical properties of the projectiles' deformable materials were modelled by means of the Johnson-Cook plasticity model, which also includes the failure criterion. The composite plate is modelled using a mixed Macro-homogenous / Meso-heterogeneous approach. In particular, the area around the impact adopts the Meso-heterogeneous modelling, in which the woven yarns and the matrix are separate parts able to interact, to increase the efficiency of the numerical methodology, allowing the modelling of the friction between the yarns, the delamination and the fibre-matrix debonding. This method needs to assign separately the mechanical properties to the fabric and the matrix as well as the damage criteria for the yarns, the matrix and the delamination. In the Macro-homogenous approach, which models the remainder of the composite plate, the yarns and the matrix are considered as a unique homogenous mean, to which equivalent orthotropic mechanical properties of the impregnated fabric are assigned. The numerical investigation mainly focuses on the residual velocity of the impacting projectiles, identifying the ballistic limit of each couple projectile-target.

Ballistic strain-rate-dependent material modelling of glass-fibre woven composite based on the prediction of a meso-heterogeneous approach

“…Moreover, damage in the back layers resulted from the tension in the SRI model, which was only noticed with the SRD model at 40 µs due to higher strength. At 40 µs (point C), the projectile is more deformed for the SRD, especially the jacket which showed an enlargement combined with peeling off of the brass layer, similar to the findings in [36], which was not noticed for the SRI model. Enlargement of the projectile, as a result of the deformation, also leads to the deformation at the front of the target in the experiments only for the SRD model, as shown in Fig.…”

Numerical simulation of high‐velocity impact on fiber‐reinforced composites using MAT_162

“…High-velocity impact on aramid fiber-reinforced composites is usually modeled using a macroscale approach where the material is considered as an equivalent homogenous medium, with no distinction between the fibers and the matrix, with orthotropic mechanical properties. [2][3][4][5][6][7][8][9][10][11] Composite MSC (MAT_161 and MAT_162) is an enhanced material model for fiber-reinforced composites developed by Material Science Corporation and implemented in the software LS-DYNA, which considers different failure modes in tension, compression, and shear with a progressive failure model. It takes into account the strain rate sensitivity of the strength and moduli properties using a logarithmic function.…”

Gelatine Backing Affects the Performance of Single-Layer Ballistic-Resistant Materials Against Blast Fragments

“…Flat-head projectiles with sharp edges, such as the one used in this study, shear through the yarns of the fabric, resulting in a lower attenuation of their energy compared to blunt projectiles (Prosser et al, 2000;Lim et al, 2002;Tan et al, 2003). Projectiles with pointed head or narrow nose such as the chisel-nosed cylinder can wedge through the fabric and thus can perforate it at lower impact velocities compared to other shapes (Prosser et al, 2000;Lim et al, 2002;Tan et al, 2003;Manes et al, 2014). Particulates from soil ejecta with small size like sand grains can infiltrate between the fabric fibers and infect the soft tissue behind (Saunders and Carr, 2018).…”

“…Due to differing geometries and compositions, these FSPs are likely to exhibit quite different interactions with protective fabrics ( Bazhenov, 1997 ; Cheeseman and Bogetti, 2003 ; Tan et al, 2003 ; Tan and Khoo, 2005 ; Li et al, 2016 ). Blunt projectiles like ball bearings do not have angled edges and cannot easily slip between the yarns so they are subjected to more deceleration by the fabric ( Bazhenov, 1997 ; Lim et al, 2002 ; Tan et al, 2003 ; Manes et al, 2014 ). Flat-head projectiles with sharp edges, such as the one used in this study, shear through the yarns of the fabric, resulting in a lower attenuation of their energy compared to blunt projectiles ( Prosser et al, 2000 ; Lim et al, 2002 ; Tan et al, 2003 ).…”