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Weidlinger Associates Inc. proposes to develop effective technology for simulating explosive detonations within civil buildings where the propagation of airblast and failure of weak internal walls are strongly coupled. We will conduct a field test program designed to complement other internal detonation testing efforts such as DTRA''s Distinct Cobra, expanding the available database. We will perfo ...

An approach for performing high fidelity modeling for blast and progressive collapse simulations of buildings will be developed. The modeling approach will allow complete simulations of building response to be performed within several days of computing time on desktop PCs. An 'easy to use' modeling interface will also be demonstrated in this effort. All response regimes will be addressed includi ...

A new type of compact induction accelerator currently under development at the Lawrence Livermore National Laboratory (LLNL) promises to increase the average accelerating gradient by at least an order of magnitude over that of existing induction machines. The machine is based on the use of high gradient vacuum insulators and advanced dielectric materials and switches. The system, called the Diel ...

DTRA and other DoD agencies are currently seeking earth penetrators with higher efficiency for reaching deeply buried targets. Current penetrator materials and designs suffer from high levels of frictional drag, unbalanced resistance due to lateral forces and localized melting of the warhead leading to shape change and further instability. General Sciences, Inc. (GSI) has developed a method for en ...

Predicting the response of building components to internal detonations is more complex than the corresponding task for external loads because of the more complex loading waveforms which include multiple reflections in the shock phase followed by a long duration pseudostatic loading that depends upon room venting. Add the possibility of additional impulsive loading from primary debris. We propose t ...

In Phase I of this effort we analyzed the structural response of a BLU 109 during typical penetration events. Based on these finite element results, we proposed and demsonstrated a simple robust concept for a passive penetrator sensor that identifies the material being penetrated and also correlates strongly with its underground trajectory. Such a sensor would obviously provide valuable informatio ...

For this Phase I SBIR program, high volumetric efficiency, energy storage capacitors are proposed using phase change ceramics. These materials are nonlinear dielectrics that make use of electric field induced antiferroelectric to ferroelectric phase transition to store more energy per volume than is possible with linear dielectrics (10 J/cm3 compared to 2 J/cm3). Furthermore phase change materia ...

On-going developmental programs have produced munitions systems which are capable of penetrating and functioning within hardened fixed ground targets. They are equipped with high explosive and fragmenting warheads to achieve target defeat but in the process produce unaccceptable target venting and agent dispersal. The need exists for a warhead payload which can effectively defeat chemical and bi ...

Low-temperature MBE grown GaAs (LT-GaAs) contains a high concentration of excess As which gives rise to ultra-fast carrier-trapping time and excellent radiation hardness. In as-grown layers most of this excess As is in the form of As(Ga) antisite defects, of which only ~1% are ionized. Thermal annealing upon overgrowth with a device structure or during device processing results in a decrease of ...

ADVANCED STRUCTURAL MATERIALS USED IN THE FABRICATION OF SUBMARINES CAN SUSTAIN LARGE STRAINS DURING THE FORMATION PROCESS CAUSED BY EXPLOSIVE LOADINGS. THE COMPUTATIONAL SOLID MECHANICS COMMUNITY HAS RECENTRLY RECOGNIZED SERIOUS SHORTCOMINGS IN CALCULATIONS USING MATERIAL MODELS IN THIS LARGE STRAIN REGION. BECAUSE OF THE IMPORTANCE OF CALCULATIONS IN UNDERSTANDING THE SHOCK RESPONSE OF SUBMARINE ...