NIST Time|NIST Home|About NIST|Contact NIST

HomeAll Years:AuthorKeywordTitle2005-2010:AuthorKeywordTitle

Algorithm for Computing the Effective Linear Elastic Properties of Heterogeneous Materials: Three-Dimensional Results for Composites With Equal Phase Poisson Ratios.


pdf icon Algorithm for Computing the Effective Linear Elastic Properties of Heterogeneous Materials: Three-Dimensional Results for Composites With Equal Phase Poisson Ratios. (646 K)
Garboczi, E. J.; Day, A. R.

Journal of the Mechanics and Physics of Solids, Vol. 43, No. 9, 1349-1362, 1995.

Keywords:

building technology; algorithms; composite materials; digital images; elasticity; finite elements; poisson ratio

Abstract:

An algorithm based on finite elements applied to digital images is described for computing the linear elastic properties of heterogeneous materials. As an example of the algorithm, and for their own intrinsic interest, the effective Poisson's ratios of two-phase random isotropic composites are investigated numerically and via effective medium theory, in two and three dimensions. For the specific case where both phases have the same Poisson's ratio (v1 = v2), it is found that there exists a critical value v*, such that when v1 = v2 > v*, the composite Poisson's ratio v always decreases and is bounded below by v* when the two phases are mixed. If v1 = v2 < v*, the value of v always increases and is bound above by v* when the two phases are mixed. In d dimensions, the value of v* is predicted to be 1/(2d-1) using effective medium theory and scaling arguments. Numerical results are presented in two and three dimensions that support this picture, which is believed to be largely independent of microstructural details.