2011-2012 Assessment of the Army Research Laboratory (2013) / Chapter Skim
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7 Weapons and Materials Research Directorate
7 Weapons and Materials Research Directorate
Pages 103-117
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From page 103... ...
Now there is a clear commitment to transforming materials computation into a reliable predictive tool, as evidenced by a new thrust toward multiscale modeling and toward model validation, verification, and uncertainty quantification.
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From page 104... ...
The restructuring of the WMRD armor technology program will help the Army to ensure that new and improved armor technologies are available to address all currently projected and future emerging threats. WMRD has streamlined its core armaments technology programs to make them consistent with the Army's current "squad-centric" focus aimed at increasing the combat effectiveness of small units.
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From page 105... ...
Furthermore, fundamental studies of polymer networks and tunable microstructures, combined with use of dynamic mechanical testing, diffusion properties, mechanical properties, and morphology studies to understand these crystalline and amorphous microstructures, will add value to the entire materials knowledge base. Many of the armor technology efforts reviewed were impressive.
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From page 106... ...
It is anticipated that further reductions in grain size to the 10-20 nm level could yield even greater improvements in mechanical properties, and thereby armor performance. A similar development is expected in Al and its alloys.
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From page 107... ...
The fundamental understanding of the structure-property-processing relationship for the polymer systems being studied in polymer networks and tunable microstructure properties is excellent. The combined use of dynamic mechanical testing, diffusion properties, mechanical properties, and morphology studies to understand the crystalline and amorphous microstructures will add value to the entire materials understanding.
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From page 108... ...
The specific work on extended solids and nano-diamonds for structural bond energy release is technically high risk and potentially high payoff. The 885A1 system successes in lethality and in reduction of environmentally sensitive materials are particularly noteworthy.
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From page 109... ...
WMRD's approach is organized in logical fashion by considering a detailed chemical kinetic mechanism, developing a reduced mechanism, and performing fluid dynamic simulation of combustion processes of IRFNA and TMEDA-DMAZ impinging jet-induced spray.1 Further consideration and treatment of the dense spray behavior will help to refine the existing model and solution. • The work on CFD simulation of interior ballistic and muzzle blast phenomena is commend able.
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From page 110... ...
In principle, accurate and efficient multiscale modeling will replace costly and time-consuming experimentation to discover process-structure-property relationships; it proceeds from a set of desired properties (or performance criteria) in a systematic way to identify material structures that display the desired properties.
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From page 111... ...
Integration over multiple length or timescales is a very challenging topic in materials engineering and the simulation of bulk properties linked to atomistic-scale attributes. The extension of mature multiple-scale modeling to manufacturing consideration will ensure that materials or designs remain in the window of practical solutions.
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From page 112... ...
To understand the potential heterogeneous reactions between the gas-phase chemical species and the instantaneous surface of the condensed phase materials, one has to consider the nanoscales in terms of active reaction sites, the microscales for chemical kinetics, the mesoscales for species mass diffusion across the layer with strong concentration gradient, and the integral scale in the processes associated with jet penetration, convective heat transfer in the flow channel, conductive heattransfer process, and mechanical deformation in the condensed phase. Besides the matter of different reaction paths, the armor material may evaporate and react with the ambient penetrating gas mixture.
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From page 113... ...
The high risk inherent in extended solids and nano-diamonds as energetic materials can be mitigated by the development of new theoretical and experimental tools that are applicable to energetic materials in general. To this end, WMRD needs to complement the traditional experimental characterization methods by collaborating with other university and national laboratory experimental programs using advanced diagnostics for assessing the atomistic, subgranular, and mesoscales, specifically, the local electrode atom probe at Iowa State University, Colorado School of Mines, and Northwestern University; the ultrafast laser at Lawrence Livermore National Laboratory and Los Alamos National Laboratory; and the hot stage scanning electron microscopy at Lawrence Livermore National Laboratory.
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From page 114... ...
The results of this initiative should be reviewed to determine if any new, low-cost technologies for producing and/or storing energy can power novel advanced protection systems and help to improve vehicle and/or soldier protection. Human Models Development of improved human models is both challenging and controversial.
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From page 115... ...
To enhance the recruiting of highly talented staff, ARL should consider offering a special fellowship that may attract exceptional new researchers to ARL. The DOE national laboratories offer special fellowships (Truman Fellowship at the Sandia National Laboratories, Oppenheimer Fellowship at Los Alamos National Laboratory, and Lawrence Fellowship at Lawrence Livermore National Laboratory)
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From page 116... ...
The WMRD armor protection technology and prototype combat vehicle armor development are internationally recognized as best-in-class, as evidenced by the half dozen or so allied countries that maintain active collaborations with WMRD in the armor technology area, as well as by Army nearreliance on WMRD-developed combat vehicle armor technologies. Compared with most of the Army, Navy, Air Force, and DOE laboratories performing weapons-related research, as well as a number of weapons laboratories in foreign countries, the integrated capabilities that WMRD has in the armaments
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From page 117... ...
WMRD has streamlined and focused its core lethality technology to make it more consistent with the Army's current "squad centric" focus aimed at increasing the combat effectiveness of small units. WMRD's solid lethality technology program will be able to deliver new understanding and many new products to the Army over the coming years.
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