An integrated approach towards future ballistic neck protection materials selection

Abstract

Ballistic protection for the neck has historically taken the form of collars attached to the ballistic vest (removable or fixed), but other approaches, including the development of prototypes incorporating ballistic material into the collar of an under body armour shirt, are now being investigated. Current neck collars incorporate the same ballistic protective fabrics as the soft armour of the remaining vest, reflecting how ballistic protective performance alone has historically been perceived as the most important property for neck protection. However, the neck has fundamental differences from the thorax in terms of anatomical vulnerability, flexibility and equipment integration, necessitating a separate solution from the thorax in terms of optimal materials selection. An integrated approach towards the selection of the most appropriate combination of materials to be used for each of the two potential designs of future neck protection has been developed. This approach requires evaluation of the properties of each potential material in addition to ballistic performance alone, including flexibility, mass, wear resistance and thermal burden. The aim of this article is to provide readers with an overview of this integrated approach towards ballistic materials selection and an update of its current progress in the development of future ballistic neck protection.

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

“…In addition, there is an overall trend that the higher the areal density, the better the ballistic fabric can reduce DoP in gelatine [category (d)], in other words result in shallower penetration. This is expected as it has been shown that the areal density directly affects the ballistic limit and energy absorption capacity of fabrics, and thus the trauma resulting from the energy that cannot be absorbed by them (Billon and Robinson, 2001;Jacobs and Van Dingenen, 2001;Karahan et al, 2008;Breeze et al, 2013a). The exception was the dilatant fabric, which demonstrated the lowest performance across assessed categories (a) to (d) despite having the second highest areal density.…”

“…V 50 of penetration into the ballistic gelatine with a depth of more than 15 mm, as an indicator of a high risk of injury. This DoP was chosen based on a range of minimum depths from the skin surface to essential structures: these were reported as 17 mm to the liver, 19 mm to the heart, and 15 mm to the common carotid artery in the lower third of the neck in the United Kingdom military population ( Breeze et al, 2013a , 2020 ); an article on a non-military population using ultrasound demonstrated this depth being 14.6 ± 5.1 mm to the femoral artery ( Seyahi et al, 2005 ) (to our knowledge, no figure has been published for a representative military population).…”

“…The study by Sakaguchi et al (2012) suggests that one or two layers of a woven aramid material can offer some protection to the extremities against low energy fragments, and that two layers of the same fabric only offer 10-25% of improvement in perforation thresholds compared to one layer. Breeze et al (2013a) also recommended the use of thin layers of ballistic material to protect the neck, which was subsequently incorporated into the under body armor vest.…”

The challenges in developing a finite element injury model of the neck to predict the penetration of explosively propelled projectiles

“…The primary FSP will be the chisel-nosed cylindrical 1.10 g FSP, which remains the internationally recognised benchmark for experimental comparisons of body armour protective materials 31 32. This particular FSP however was originally chosen as it was the most common fragment produced by one particular World War I ordnance casing and therefore may not be representative of the fragments produced by contemporary explosive devices 32.…”

“…The primary FSP will be the chisel-nosed cylindrical 1.10 g FSP, which remains the internationally recognised benchmark for experimental comparisons of body armour protective materials 31 32. This particular FSP however was originally chosen as it was the most common fragment produced by one particular World War I ordnance casing and therefore may not be representative of the fragments produced by contemporary explosive devices 32. Recent analysis of CT scans performed on UK soldiers with penetrating explosive fragments retained in their necks has suggested that the smaller 0.49 g cylindrical FSP may instead be a more representative testing projectile for ballistic protective materials to protect the neck 31.…”