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Newark, DE, United States

Lopatnikov S.L.,University of Delaware | Lopatnikov S.L.,Center for Composite Materials | Gillespie Jr. J.W.,University of Delaware
Transport in Porous Media | Year: 2010

We present here the approach to the theory of fluid-filled poroelastics based on consideration of poroelastics as a continuum of "macropoints" (representative elementary volumes), which "internal" states can be described by as a set of internal parameters, such as local relative velocity of fluid and solid, density of fluid, internal strain tensor, specific area, and position of the center of mass of porous space. We use the generalized Cauchy-Born hypothesis and suggest that there is a system of (structural) relationships between external parameters, describing the deformation of the continuum and internal parameters, characterizing the state of representative elementary volumes. We show that in nonhomogenous (and, particularly, nonlinear) poroelastics, an interaction force between solid and fluid appears. Because this force is proportional to the gradient of porosity, absent in homogeneous poroelastics, and one can neglect with dynamics of internal degrees of freedom, this force is equivalent to the interaction force, introduced earlier by Nikolaevskiy from phenomenological reasons. At last, we show that developed theory naturally incorporates three mechanisms of energy absorption: visco-inertial Darcy mechanism, "squirt flow" attenuation, and skeleton attenuation. © 2010 Springer Science+Business Media B.V. Source

News Article
Site: http://www.materialstoday.com/news/

TPI Composites Inc has been awarded a US$3 million program by the U.S. Department of Energy’s Office of Energy Efficiency & Renewable Energy (EERE) to design, develop, and demonstrate a lightweight hybrid composite door. TPI will be leading a team of industry and academic participants with knowledge in vehicle design and composite materials, including Creative Foam Corporation, Hexion Inc., KraussMaffei, SAERTEX USA, LLC, Center for Composite Materials at the University of Delaware, and a global automotive OEM. ‘We are excited about the opportunity to design, develop and validate the materials and manufacturing technologies that can transition lightweight structural composites into the high volume automotive mainstream,’ said Steve Lockard CEO & President TPI Composites. Part of the challenge of widespread composite adoption in automotive applications is the ability for composite structures to achieve cost targets and high volume production rates.  The composite door program will focus on meeting all structural, safety and noise, vibration, and harshness performance goals while addressing cycle time and cost constraints. This story is reprinted from material from TPI Composites, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.

He Y.-R.,Harbin Institute of Technology | Wang X.-Z.,Harbin Institute of Technology | Han J.-C.,Harbin Institute of Technology | Han J.-C.,Center for Composite Materials | And 3 more authors.
Journal of Propulsion and Power | Year: 2014

One of the greatest challenges of hypersonic vehicles is their thermal protection and, more specifically, the cooling of their engine. To simulate the behavior of a complete actively cooled thermal protection system, a computational fluid dynamics and finite element analysis coupling method is applied to calculate the fluid/thermal/stress distributions for steady-state flight conditions. Work has been done on four different Ni-based alloys and three different panel structures. Temperature and stress profiles at the outlet cross section show that the maximum temperature and stress happen on the side that is close to the combustion chamber, and so this is the section on which the active cooling system should focus. It is better to have small rounded chamfers in the panels to decrease the stress concentration at the corners. Failure maps are presented for four Ni-based alloys showing the comparison of their thermostructural performance, which will be helpful for the selection of the materials in an active cooling system. Copyright © 2013 by the American Institute of Aeronautics and Astronautics, Inc. Source

Leng J.,Center for Composite Materials | Liu L.,Center for Composite Materials | Liu V.,China Institute of Technology
JEC Composites Magazine | Year: 2012

The applications for shape -memory polymers and composites in aerospace have been widely studied since the 1980. As shown in this paper, these promising smart materials are being particularly developed and qualified for space deployabes struc-tures morphieoptical reflectors, smart textiles and fabrics. Source


Agency: Department of Defense | Branch: Army | Program: STTR | Phase: Phase I | Award Amount: 100.00K | Year: 2000


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