Numerical Modeling of Multi-Phase, Multi-Material Blast- Structure Interactions

This paper describes results of a combined experimental and computational effort intended to validate predictions of a coupled CFD/CSD methodology of a multi-plate steel structure response to blast loading. To improve our understanding of the complex controlling physical mechanisms we formulated a simplified, multi-step approach. First, we investigated a precision test of a single event, the response of a single steel plate to a close-in bare charge. Next, we added a second plate to examine the response of the second plate to blast and flyer plate loading. Finally, we placed water-filled tube s under the first plate, to investigate the feasibility of using water tubes to disperse and di ssipate flyer-plate kinetic energy. The modeling of blast and structure (flyer plate) inter action with water required the development of a new numerical algorithm that combines flow solvers for both the gas and the liquid via an immersed body approach. Both solvers run concurrently. In the gas phase region (i.e. compressible flow), the velocities of the liquid were imposed wherever liquid is present. For the liquid region (incompressible (+VO F)), the pressures of the gas region were imposed wherever gas was present. This multiphase flow solver is then coupled to our structural mechanics solver to calculate structural response to blast and the feasibility of using fluid dampers. The results demonstrate that t he approach taken here is capable of efficiently modeling complex multiphase problems.