This paper discusses the general conditions relating to ballistic head protection, analyzing the risks that may occur on contemporary battlefields. A thorough literature review has enabled us to present development trends for helmets used in the largest armies in the world. The authors have focused on impacts to the helmet shell, overloading the entire helmet-protected head–neck system. The main objective of this study is to investigate the protective capability of a helmet shell when subjected to projectile–helmet contact, with contact curvature taken as being an indicator of the impact energy concentration. Blunt head trauma was estimated using backface deformation (BFD). The Wz.93 combat helmet was used for testing. Analytically, dependencies were derived to determine the scope of BFD. A five-parameter model of the helmet piercing process was adopted, thus obtaining the optimal BFD range. Verification of theoretical considerations was carried out on a specially developed research stand. In the ballistic tests, dynamic deflection of the helmet’s body was registered using a speed camera. On the impact testing stand, a fragment of the helmet was pierced, producing results in the low impact velocity range. Data have been presented on the appropriate graph in order to compare them with values specified in the relevant standard and existing literature. Our results correlate well with the norm and literature values.
20 March 2016 in Eksploatacja i Niezawodność – Maintenance and Reliability
The paper presents the puncture resistance of the material, that is under the influence of highly deformable projectile, depending on changes of material’s yield strength. The simulation has been conducted using mobile cellular automata (MCA) with authors’ own software. The simulation took into account the elasto-plasto-viscous properties of the material as well as surface and internal friction. The selected results are illustrated in terms of piercing the multilayer material with chosen projectiles of kinetic influence in the range of impact velocity between 300 and 1000 m/s.