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SUNMONTUEWEDTHUFRISAT
Events for May 08, 2008
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Carbon Foams and Carbon Nanotubes: Modeling Based on Structural Mechanics
Thu, May 08, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Dr. Xin-Lin Gao, Professor Texas A&M UniversityAbstractCarbon foams, first developed at the Air Force Research Laboratory (AFRL) in the 1990s, are rapidly emerging as a new class of ultra-light cellular materials for structural and thermal management applications. They are blown from a coal-based or chemically synthesized pitch precursor through a bubble forming process and have a 3-D open-cell structure, with the cell size ranging from tens to hundreds of microns. Recent research efforts have been focused on how to optimize the foam properties based on reliable processing-structure-property relationships. In the first part of this seminar, three micromechanical and computational models developed by the speaker's group using structural mechanics will be discussed. The first two are based on a single unit cell (a tetrakaidecahedron), with one using Castigliano's second theorem and the other employing the matrix method for space frames. The third model accounts for the randomness in foam microstructures and involves hundreds of cells, which is developed using the Voronoi tessellation technique and the finite element method.The discovery of carbon nanotubes in 1991 is one of the key breakthroughs that have taken us into an emerging era of nanotechnology. Nanostructured materials will be playing a critical role in the new era. In the second part of this seminar, two multi-scale analytical and computational models developed by the speaker's group using structural mechanics and energy principles will be presented. One is a shear-lag model for estimating load transfer in carbon nanotube-reinforced polymer matrix composites based on molecular structural mechanics and elasticity, and the other is a continuum-based model for predicting Young's modulus of single-walled carbon nanotubes developed using finite deformation kinematics and energy equivalence.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
