Weapons Effects FRMs for Small Munitions on Urban Reinforced Concrete Walls/Slabs

A 24-month SBIR Phase II Project titled"Weapons Effects FRMs for Small Munitions on Urban Reinforced Concrete Walls/Slabs."The stated objective of this solicitation topic is to develop High-Fidelity Physics-Based (HFPB) Fast-Running Models (FRMs) for simulating the effects of small weapons in urban structures and materials. This proposal covers RC walls and slabs while an accompanying proposal covers masonry walls. The main focus of this project is to develop FRMs to predict secondary debris generated when small cased munitions detonated at impact or at partial penetration on urban walls. First we propose to validate the selected HFPB modeling approach by comparing its predictions with experiments conducted by JLF over several years. Then, we will exercise the validated HFPB tool in a parameter space to generate virtual data to develop and calibrate our FRMs. In this Phase II, we proposed to develop FRMs to predict (a) hole size, (b) residual capacity index, (c) debris mass, (d) correlated debris mass-velocity distribution for RC walls. BENEFIT: In recent years, the US military finds itself more and more involved in urban warfare. In urban warfare or MOUT armed forces have to exhibit caution so that their actions will not harm civilians and friendly forces in the area. These precautions exclude the use of large weapons and therefore the military is extremely interested in the use of more precise small weapons. These small weapons are often used to breach urban walls and can be inert projectiles or explosive projectiles (cased weapons) that a) detonate upon impact or b) set for a delayed detonation during partial penetration in order to maximize damage. The physics of the inert or explosive impacts and the resulting breakup and debris generation of these munitions are very complex and validated numerical methods do not yet exist. Therefore, there is a need to develop validated small munitions models capable of determining the consequences of their use in order to assist military planners and soldiers in the field. The HFPB models that can simulate the complex phenomena involved in the impact of an inert/explosive ammunitions require vast computer resources and skilled personnel to setup and run the models; this is not suitable for military planners and commanders who need quick answers or to perform"what-if"studies. Therefore, it is necessary to develop FRMs that capture the essence of the HFPB simulations and run very quickly. The FRMs also need to provide information to the analysts/planners on their predictive accuracy (confidence in the results) given the inherent uncertainties in the modeling process. For example, commanders might like to know what munitions to use and where to impact a wall of a particular construction material (e.g., concrete) in order to breach the wall and create a hole that will enable a soldier into a building. They might also like to know the how injurious the debris thrown from the wall breach will be to occupants or to critical assets. The fast-running debris throw models developed in this project will support these kinds of decisions.