A comparison of hydrodynamic and analytic predicted blast pressure profiles

摘要

Modeling the structural response to blast relies on accurate descriptions of the blast loading pressure profiles. Traditionally, empirically based blast pressure histories are used for this modeling. However, the structural response and geometric configuration can strongly affect the blast loading profile, particularly for close-in blast loading configurations. As a result, high rate continuum modeling is being increasingly applied to directly resolve both the blast profiles and structural response. A variety of computer models exist for the purpose of analyzing blast pressures associated with different types of explosive charges and ranges. These computer models range from simple empirically based analytic models based off of the Hopkinson cube root scaling to multi-physics high rate finite element approaches, commonly known as "hydrocodes", which are capable of tracking shocks through the conservation equations of continuum mechanics. The purpose of this paper is to provide comparisons of blast profiles predicted by analytic models with a hydrodynamic model at various standoffs. Three computer models; BlastX, Conwep, and ALE3D, were used to model the detonation of five pounds of TNT. Pressure profiles for various standoffs were gathered from each computer model and compared. The ALE3D result is greatly dependant on the mesh size and appears to converge to the BlastX and Conwep solutions with increased mesh resolution.