2Sth DoD Explosive Safety Seminar Anaheim, California COMPARISON OF DEBRIS TRAJECTORY MODELS FOR EXPLOSIVE SAFETY HAZARD ANALYSIS

Robust prediction of the motion of debris from explosions is critical to the estimation of separation distances, fragment density, and debris lethality in explosive safety hazard analysis. Debris dispersion models have been developed and applied to many specific types of hazardous debris (ranging from masonry, concrete, structural steel elements, soil and rock ejecta, to bomb fragments). These models generally use 2-D (degree-offreedom) or 3-DOF trajectory calculations and consider only the drag component of the aerodynamic force vector (e.g., DOEflIC1 1268 [ 19801 , Huang [ 19841 , McCleskey [1988], Bowles and Oswald [1990]). For many debris geometries (such as plates, slender fragments, and structural elements with high slenderness ratios), drag component trajectory models underpredict maximum debris range and dispersion. In addition, if the potential for spin-stabilized motion exists, the safety distance for plate or disk shape fragments can significantly exceed that which would be predicted for random tumbling or other non-spin-stabilized motion [Twisdale, 19841.