Friday, May 21, 2010

SEMINARI / SEMINARIO / SEMINAR

Tuesday, 1st June 2010, 12:00h

Molecular Dynamics Simulation of Structure and Mechanical Properties of Silica Aerogels and Xerogels
Prof. Ever J. Barbero

Professor, Mechanical and Aerospace Engineering, College of Engineering and Mineral Resources at West Virginia University

Location/Lugar: Sala O.C. Zienkiewicz, CIMNE-Barcelona, Edificio C1, Campus Norte UPC

Curriculum

Ever J. Barbero, ASME Fellow and SAMPE Fellow, is recognized internationally for his work on material models for composite materials. He is the author of "Introduction to Composite Materials Design," Taylor and Francis (1st Ed. 1999, 2nd Ed. 2010), and "Finite Element Analysis of Composite Materials," Taylor and Francis (2007), several book chapters, over 100 peer-reviewed publications, numerous conference papers, and mentor of numerous MS and Ph.D. graduates currently serving leadership positions in academia and industry worldwide. He holds two US Patents, #6,455,131 (2002) and #6,544,624 (2003). He received the AE Alumni Academy Award for Outstanding Teaching (1999) and numerous research awards. As former department chair, he led the Department in accomplishing ABET accreditation twice, as well as substantial growth of all productivity including research expenditures, undergraduate and doctoral enrolment and so on. Eleven new faculty were added to the department in the period 2002-2009. He is currently finalizing the 2nd edition of his undergraduate textbook and working on a book chapter about physical aging of polymer composites, as well as being engaged in several research projects in materials science.

Abstract

Molecular Dynamics Simulation leading to structural and mechanical properties of porous silica is presented. The procedure to prepare the samples is described. The resulting porous structures have densities in the typical range of Aerogels. The structure of the samples is characterized by fractal dimension using two different methods, pair distribution function and simulated scattering experiments. Fractal dimensions are found to be in good agreement with published data from physical experiments and comparable computer simulations. Further, modulus and strength are studied through the simulation of a tension test. They are shown to relate to density by a power law characterized by exponents that are in excellent agreement to published data from physical experiments.  The results prove that direct expansion, coupled with thermal processing of the sample leads to systems that resemble well the structure and mechanical properties of silica aerogels.

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