Comparison of Head Injuries as Predicted by Three Different Displacement Velocity Models

摘要

Head injuries cause many of the fatalities produced by blast effects. In such injury predictions, the skull is more vulnerable to dynamic pressure than to overpressure. Dynamic pressure, resulting from the blast wave sweeping over the human body, causes the body to be swept along behind the wave at some displacement velocity. Injuries occur when the moving body encounters stationary, solid structures. The displacement velocities for various skull injury levels are known. Solving the motion equation for a body in a transient flow field yields the displacement velocity as a function of peak overpressure and impulse. Baker, et al. and Mercx previously attempted this computation, but in each case significant deficiencies occurred. In Baker's analysis, both diffraction pressure and drag loading were computed, but the drag on the human body contained no adjustment for the object's motion. Thus, some of Baker's displacement velocities exceeded the particle velocity behind the blast wave, (a physically impossibility), resulting in very inaccurate curves at low peak overpressures.