Effective Elastic Moduli of Nanocomposites with Prescribed Random Orientation of Nanofibers
V.A. Buryachenko and A. Roy
University of Dayton Research Institute, US
Keywords: microstructures, elastic moduli, nanocomposites
Experimental research and molecular dynamic simulation proved that nanofibers can be effectively considered in the framework of continuum mechanics as the homogeneous prolate spheroidal homogeneous inclusions with a large aspect ratio. Nanocomposite is modeled as a linearly elastic composite medium, which consists of a homogeneous matrix containing a statistically homogeneous random field of nanofiers with prescribed random orientation. Estimation of effective elastic moduli of nanocomposites was performed by the version of effective field method (MEF, see for references and details Buryachenko, 2001) developed in the framework of quasi crystalline approximation when the spatial correlations of inclusion location take particular ellipsoidal forms. These ''correlation hole'' including the representative fibers are prohibited for the location of centers of surrounding fibers (since they cannot overlap) and compatible with mutual orientations of fibers. The independent justified chose of shapes of inclusions and correlation holes provide the formulae of effective moduli which are completely explicit and easily to use. However, the main advantage of the proposed approach is that it is free from some of drawbacks of competitor approximation such as that Mori-Tanaka scheme, which can generate tensors of effective moduli which fails to satisfy a necessary symmetry requirement. The parametric numerical analyses revealed the most sensitive parameters influencing of the effective moduli which are defined by the axial elastic moduli of nanofibers rather then their transversal moduli as well as by the justified chose of correlation holes, concentration and prescribed random orientation of nanofibers.
Nanotech 2004 Conference Technical Program Abstract