Next-generation Debris Prediction Method for Hardened Structures

This project will provide Fast-Running Models (FRMs) for analyzing debris hazards from internal detonations in ammunition storage magazines. The FRMs will be better than a “back of the envelope” prediction, but not as expensive (time or money) as a High-Fidelity Physics-Based (HFPB) solution. No FRM currently exists to provide the breadth and depth of analytical capabilities required by the explosives safety community. Existing FRMs may provide part of what is required but tend to be conservative, when a “conservatism neutral” approach is needed. In Phase I, the team extended HFPB analysis methods using stochastic methodologies and procedures to predict the structural response, secondary debris, and airblast generated by bare high-explosive charges detonated and contained inside a reinforced concrete containment structure. The results from these stochastic coupled HFPB (SC-HFPB) methods, which utilized novel coupled Meshfree Computational Solid Dynamics and Computational Fluid Dynamics (CSD/CFD) computational methods, were demonstrated as feasible through comparing predictions with data available from the Kasun III experiments. Concepts for using the HFPB computational results to generate FRMs for debris generation analysis and debris density prediction were developed and described in the Phase I Final Report. In Phase II, the stochastic analysis methods for both structural and explosives effects characterizations will be completed in preparation for validation against test data and for developing two prototype FRMs, one with the capability to predict debris generation (Debris Analysis Tool (DAT)) and one that calculates debris density (Debris Density Calculator (DDC)), from an internal detonation in a magazine. The following objectives are proposed: 1.            Complete and validate the SC-HFPB models for explosives effects, structural response, secondary debris, and airblast. 2.            Identify and select parameters for generating response data for magazines. 3.            Produce a structural response (debris generation) database using the SC-HFPB models. 4.            Develop prototype DAT and DDC FRMs. The Phase II project will be completed in three spirals (development cycles coinciding with the base and two option years). Each spiral will include validation activities, enhancement of SC-HFPB capabilities, new FRM versions, and a plan for the next spiral. The intent is to develop a robust model for a limited set of magazines in the first spiral and to expand the number of magazines that can be modeled in subsequent spirals.