A Framework to Integrate Performance of Helmet Systems for Blast Overpressure, 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 U.S. Warfighters have increased with the prevalence of buried improvised explosive devices simultaneously producing overpressure, blunt and ballistic impact effects, as well as thermal loading in extreme desert conditions. The literature to date does not show any research 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 (CFD) and structural mechanics approaches presented by the authors earlier. The thermal loading and its effects are modeled as forced convection due to ambient directional winds 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 consider two different configurations of helmet systems in this paper and present the results in detail.