LAUSR

Primary blast wave impact on military personnel is of major concern, particularly as it relates to traumatic brain injury. To gain insights into the brain’s response to primary blast impact, the current research employed a surrogate head form filled with biogel brain simulant and subjected it to primary blast waves propagating 180 mm from a 1.7-g cyclotrimethylene trinitramine Class 5 (RDX) explosive charge. The blast impacts to the surrogate head were investigated using combined approach of experiments and computations. More specifically, the combination of (1) high-speed imaging techniques, (2) embedded intracranial pressure sensors, and (3) numerical simulation techniques was used to study the blast wave/head interactions in terms of the external impact loading, intracranial pressures, and deviatoric stresses. The experimental and computational results show that the intracranial wave generated in the surrogate brain was a consequence of blast interactions with the surrogate skull. The resulting intracranial pressures were shown to be within threshold limits that could induce minor or mild traumatic brain injuries. Strong oscillations between compression and volumetric tensions were pronounced in the anterior region of the surrogate brain following frontal blast impact. Focal regions of elevated stress were captured in the simulation at the posterior region of the surrogate brain resulting from multiple reflections off the back of the skull. Deviatoric stress distributions were also revealed at the skull/surrogate brain interface where more dominant forces appeared at the base (interface) of the skull. These results indicate the potential for shearing/tearing of brain tissue material due to blast loading.