On a Framework to Integrate Performance of Helmet Systems for Blast, Blunt Impact and Thermal Loading

Abstract

Helmets have evolved through improvements in shell and suspension materials, and better designs that can absorb ballistic and blunt impact energy. In the past 20 years, threats to US Warfighters have increased with the prevalence of buried improvised explosive devices (IED) simultaneous producing overpressure, blunt and ballistic impact effects, as well as thermal loading in extreme desert conditions. To date, no research has been found in literature that integrates multiple types of loading in helmet system design and performance analysis. The scope of this paper is to integrate such loadings into a design framework that enables trade space analysis across multiple threats. Blunt impact and blast overpressure loadings are simulated using computational fluid dynamics and structural mechanics approaches presented by the authors earlier. The thermal loading and its effects are modeled as buoyancy-driven natural convection, i.e., flow generated by the body’s thermal plume, and forced convection due to ambient wind to assess each design’s efficiency in facilitating evaporative cooling via perspiration and quantified by transport of moisture-laden air away from the head. Blast overpressure and blunt impact loadings, along with thermal loading, are used for multiple configurations of the helmet suspension system as representative cases. The results from the simulated cases are integrated within a framework combining the effects of the loadings to assess helmet system design. We hope that this paper suggests ways to generate a functional representation integrating multiple loadings in protection system design.