Hydrodynamic Modeling of Detonations for Structural Design of Containment Vessels

Los Alamos National Laboratory (LANL), under the auspices of the U.S. Department of Energy (DOE) and the National Nuclear Security Administration (NNSA), has been conducting confined high explosion experiments utilizing large, spherical, steel pressure vessels to contain the reaction products and hazardous materials from high-explosive (HE) events. Structural design of these spherical vessels was originally accomplished by maintaining that the vessel’s kinetic energy, developed from the detonation impulse loading, be equilibrated by the elastic strain energy inherent in the vessel. In some cases, the vessel is designed for one-time use only, efficiently utilizing the significant plastic energy absorption capability of ductile vessel materials [1]. Alternatively, the vessel can be designed for multiple use, in which case the material response is restricted to the elastic range [2]. Within the last decade, designs have been accomplished utilizing sophisticated and advanced 3D computer codes that address both the detonation hydrodynamics and the vessel’s highly nonlinear structural dynamic response. This paper describes the hydrodynamic modeling of HE reaction products phase, which produces transient pressures resulting in an impulsive load on the vessel shell. Modeling is accomplished through either (a) empirical/analytical methods utilizing a vast experimental database developed primarily for the Department of Defense (DoD) or (b) through application of numerical hydrodynamics codes, such as the Sandia National Laboratories (SNL) shock-wave physics code, CTH [3], which accurately model the thermochemistry and thermophysics of a detonation. It should be noted that this paper only addresses blast load prediction using the methods stated and does not include an assessment of structural response methods.