Non-Spherical Blast in a Cluttered Environment

ABSTRACT: The purpose of this project is to develop and demonstrate, validated and verified software that will allow realistic blast pressures to be replicated in a completely Lagrangian simulation while minimizing the impact on overall run time and capturing pertinent effects within cluttered environments. These effects include non-spherical explosive charges, moving explosive charges, strong shocks, reflections, and shadowing. During Phase I, RHAMM Technologies, LLC successfully developed a prototype user-defined load (Rhammload blast2), compatible with LS-DYNA"s Lagrangian mode, which is capable of modeling all the effects outlined in the original SBIR topic. We have also shown that test data and hydrocode simulations are available to validate the new blast load code. In Phase II we will strive to verify the Rhammload blast2 software; validate the Rhammload blast2 software; optimize the Rhammload blast2 software for speed and efficiency; document Rhammload, describing the installation, usage, and theory; update all existing JASPO-developed LS-DYNA threat models; add the ability to use a tabular reference blast; and extend Rhammload further by incorporating features such as the ability to handle shock diffraction around corners and improving blast pressures on yielding structures. BENEFIT: Benefits of this technology and the proposed approach include the military benefits of enhanced survivability for our aircraft. Rhammload will provide to an analyst, for the first time, the ability to model realistic blast effects in an all Lagrangian simulation allowing faster runtime and larger, more complex simulations not previously possible with pure Euler or coupled Euler-Lagrange methods. In addition, this project will produce updated versions of all JASPO LS-DYNA threat models that take advantage of the new Rhammload. This will directly improve the survivability of future aircraft. Mainstreaming the computer aided testing (CAT) concept in the survivability community will also be a benefit of this proposal. Enhancing aircraft survivability is not just either a simulation or a testing issue. To get the most survivability for your dollar, you need both. You need fast running high fidelity simulation (like Rhammload can provide) to help choose the most beneficial tests. You need realistic, well instrumented tests to ensure you''re capturing a"real world"survivability picture. Finally, you need to use the test data to validate additional simulations of excursions from the test scenario. RHAMM"s strategy for commercialization is straightforward. We have two options that we will pursue. First, RHAMM Technologies will endevor to sell or license Rhammload to LSTC for inclusion into LS-DYNA. Alternatively, we will sell the userload directly to other companies as an add-on module for LS-DYNA. Second, the intellectual capital that will be amassed through the completion of this work will enable RHAMM to play a significant role in supporting programs engaged in computer aided testing or threat modeling. This role could yield several million dollars as a welcomed commercialization result with substantial growth probability. Phase III will be focused on enhancing the Phase II Rhammload software to better model non-military threats (explosions not created by munitions). This would make Rhammload an important tool in guaranteeing the safe handling of explosive materials (fuel tanks, paper dust, mine safety studies, etc.) as well as Homeland Security issues like improvised explosive devices (IED).