Sullivan B.J.,Materials Research and Design, Inc.
Journal of the Franklin Institute | Year: 2015
For groundbreaking contributions to the micromechanics of composite materials, thereby enabling practical engineering designs of composite structures and for significant contributions to the development and formulation of methodologies for the calculation of the electrical, physical, thermal and mechanical properties of heterogeneous materials. © 2015, Elsevier Ltd. All rights reserved. Source
Sullivan B.,Materials Research and Design, Inc.
Journal of the Franklin Institute | Year: 2015
John T. Chambers receives the 2012 Bower Award for Business Leadership for shaping Cisco Systems, Inc. into one of the world's most widely respected and successful technology companies, providing business and consumer technologies that allow millions of people to connect to each other through computer networking and the Internet, and for his leadership by example in corporate responsibility and personal philanthropy. © 2015, Elsevier Ltd. All rights reserved. Source
Herbst J.F.,General Motors |
Hector L.G.,General Motors |
Wolf W.,Materials Research and Design, Inc.
Physical Review B - Condensed Matter and Materials Physics | Year: 2010
Systematic properties of the A GaH4 alkali gallium hydrides (A=Li, Na, K, Rb, and Cs) are investigated within density functional theory. Seven ground-state crystal structures are identified, with two energetically indistinguishable structures found for both LiGaH4, whose structure is as yet undetermined experimentally, and CsGaH4. Born effective charge tensors, static and high-frequency dielectric tensors, and phonon dispersion relations incorporating longitudinal-optical/transverse-optical mode splittings are computed. Our results indicate that LiGaH4 and NaGaH4 have technologically interesting standard enthalpies of formation near -30 kJ/mole H2. We find, however, that LiGaH4 is thermodynamically unstable with respect to both LiGa and LiH, providing a possible explanation for its challenging synthesis. The Born stability criteria are evaluated with the computed elasticity tensor components, Cij. All seven structures are found to be both elastically and vibrationally stable. © 2010 The American Physical Society. Source
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 124.94K | Year: 2015
To address the need for low-ballistic coefficient aeroshells with minimal impact on vehicle weight, NASA is investigating flexible thermal protection system (TPS) options. These designs typically consist of a flexible three-directional (3D) woven carbon cloth that can be stowed during flight and deployed on command to serve as a semi-rigid aeroshell during atmospheric entry. For some planned entry trajectories, the woven TPS is subjected to short duration, but extremely high heat flux levels. Since current plans call for the use of as-received non-heat treated carbon fibers in the WTPS, MR&D aims to investigate whether exposure to high temperature, short duration temperatures alters the graphitic microstructure and thus the properties of PAN-based carbon fibers.
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 99.91K | Year: 2011
As space exploration and hypersonic cruise technologies develop, the focus has shifted towards the development of lightweight, fully reusable and lower cost vehicles. The current state-of-the-art (SOA) is taking an incremental improvement step over the Space Shuttle TPS approach. All-ceramic matrix composite (CMC) body flaps developed for the X-38 vehicle were shown to offer considerable mass savings as well as increased durability and impact resistance. The next step in advancing the state of the art is to increase the confidence in the design and manufacturing quality of a full CMC control surface for hypersonic vehicles. Within this effort, Materials Research & Design (MR & D) is proposing a trade study which will investigate various control surface manufacturing and material options for the ruddervator design of X-37B Orbital Test Vehicle. For the proposed Phase I program, MR & D has chosen an integrally fabricated all-CMC control surface, a mechanically fastened-individually fabricated fully-CMC control surface, and a CMC sandwich structure control surface to be the three candidate design structures in a trade study. Potential material candidates include, but may not be limited to, CVI C/SiC, C-C with 1-2 SiC cycles for oxidation protection, S200 Nicalon/SiNC from ATK COIC, and SiC/SiC.