Physics of shock tube simulated IED blast for mTBI research

The objective of this research is to understand the blast propagation into the human skull and brain causing mTBI and use this knowledge for enabling design of effective protection measures against them. A shock tube including sensor system was optimized to simulate realistic IED blast profiles obtained from full scale field tests. Shock tube experiments and numerical simulations are combined in order to gain confidence in the measure devices (i.e. pressure, strain gages, etc) and understand the mechanisms of wave propagation in air and simplified ‘head’ surrogate. A cube and a sphere containing gelatin (brain simulant) are used for this purpose. The shock tube experiments are used as a reference to validate the numerical simulations combining a CFD (computations fluid dynamics) model of the air and a finite element model of the simplified ‘head’ surrogate. An accurate IED shock tube pressure-time profile depends on the dimensions of tube and driving unit and is highly sensitive to the exact location in the tube. The validity of the results depends on an accurate material characterization in the highly dynamic blast loading rate. Parameters necessary to characterize an IED blast wave will be explained as well as effect of material characteristics, skull openings etc. on the blast wave propagation into the simplified head surrogate