Rapid Quantification of Energy Absorption and Dissipation Metrics for PPE Padding Materials
Final technical rept. 22 Apr-22 Oct 2009
TEXAS UNIV AT SAN ANTONIO
Pagination or Media Count:
The use of energy-absorbingdissipating materials in personnel helmets to reduce the effects of blast pressures can have unanticipated adverse effects. The presence andor configuration of these materials can focus energy in such a way that it can cause unforeseen traumatic brain injuries. The purpose of this research is to develop a innovative modeling and simulation approach for rapidly quantifying metrics that characterize the energy absorptiondissipation capacity of candidate materials to be used in retrofitted helmets and other personnel protective equipment PPE. Metrics such as the saturation point of the material with respect to maximum blast loads, and the ratio of the total blast energy to the energy that is transmitted to the victim, are used to rate two candidate materials. Quantification of these metrics is accomplished using dynamic modeling and simulation technique, facilitated by impedance-based bond graphs. These models include novel elements whose constitutive laws are defined by fractional derivatives, which capture frequency-dependent viscoelastic and viscoinertial properties of energy absorbingdissipating materials. Input forces caused by blast pressures, determined from computational fluid dynamics CFD analysis and simulation of common blast sources encountered in current conflicts, are used to generate the externally applied force inputs for material modeling simulations.
- Safety Engineering
- Protective Equipment