Ballistic impact wave and bulge profile propagation characteristics and blunt injury assessment of UHMWPE laminate composite

Abstract

Amid escalating localized conflicts worldwide, the elucidation of the mechanisms and quantification blunt trauma the emergency services and military personnel confronted becomes imperatively. However, the understanding of bullet-induced bulge formation on the laminate's back face, impact wave propagation, and consequent trauma assessment methods remains incomplete. This study applies 3-dimension digital image correlation (3D-DIC) method to reveals these phenomena by utilizing a lead-core bullet traveling at 334.93 m/s to impact an ultra-high molecular weight polyethylene (UHMWPE) laminate. The results show that the initial transverse propagation velocity of bulge profile is 24.79% smaller than the theoretical calculation, which indicates the reduction caused by cohesive matrix. The transverse wave demonstrates a double exponential attenuation pattern, which could be decomposed into two single exponential attenuation curves. The bulge profile shows hyperbolic pattern, which reveals the stability of the bulge shape and the temporal evolution pattern. Increasing the laminate-body gap leads to a decline in Blunt Criterion (BC) and the Abbreviated Injury Scale (AIS) values reduce from 2 to 0 correspondingly. The numerical model confirms the compression wave velocity as 1447.77 ± 123.10 m/s in the thickness direction and 9542.86 ± 3087.75 m/s in the fiber direction. These findings reveals and quantified the propagation patterns of back bulge and compressive wave, and thus could provide data-driven insights to improve body armor performance and blunt trauma assessment for individual soldiers.