There is a pressing need to improve protection against brain injuries amongst our troops with Traumatic Brain Injury considered the signature injury of the wars in Iraq and Afghanistan. Potential sources of mild Traumatic Brain Injury include both blunt impact and blast pressure waves (shock-fronts). This research will focus on the development of new polyurethane foam systems that build on the performance characteristics of the proprietary foam used in the current Team Wendy helmet pads. These performance characteristics will include quasi-static and dynamic compressive stress-strain across a range of strain rates and temperatures as well as blast pressure mitigation though shock-tube experiments. These material properties will be optimized through reformulation of the foam system to achieve performance closer to theoretically ideal. In addition to these polyurethane foam systems two additional routes will be considered; foams enhanced with shear-thickening-fluids and new thiol-ene and thiol-urethane/urea based energy absorbing materials. The potential for increased rate sensitivity of foams enhanced with shear-thickening-fluids will be determined through dynamic and static compression tests. The potential performance benefits of new thiol-ene and thiol-urethane/urea based energy absorbing materials will be determined through comparison of dynamic thermomechanical properties to those of the polyurethane foam systems.
Keywords: Blunt Impact, Helmet Pad, Blast, Acceleration, Mild Traumatic Brain Injury, Shear Thickening Fluid, Polyurethane Foam, Advanced Combat Helmet
