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Author
Day, A. R. | Snyder, K. A. | Garboczi, E. J. | Thorpe, M. F.
Title
Elastic Moduli of a Sheet Containing Circular Holes.
Coporate
Marquette Univ., Milwaukee, WI National Institute of Standards and Technology, Gaithersburg, MD Michigan State Univ., East Lansing, MI
Journal
Journal of the Mechanics and Physics of Solids, Vol. 40, No. 5, 1031-1051, 1992
Keywords
circular holes | elastic moduli | digital-image-based model | numerical method | experiments
Abstract
We apply computer simulation techniques to obtain the elastic moduli of a matrix containing circular holes. As the area fraction of holes increases, the Young's modulus of the composite decreases from Eₒ until it eventually vanishes at the percolation threshold. We study three distinct geometries: (a) periodically centered circular holes on a honeycomb lattice, (b) periodically centered circular holes on a triangular lattice, and (c) randomly centered circular holes. All three cases have the same dilute limit that can be calculated exactly. By examining the narrow necks between adjacent circles, we have calculated the critical behavior for the regular cases and obtain critical exponents of 1/2 or 3/2, depending on the local breakdown mode at the necks. For (c) we compare our results with an effective-medium theory, which predicts that the Poisson's ratio tends to 1/3 as the percolation threshold is approached, independent of its value in the pure system. Our results are also compared with recent experimental results. Basedon this work, we propose that the relative Young's modulus E/Eₒ of a two-dimensional sheet containing circular holes, overlapping or not, is the same for all materials, independent of the Poisson's ratio vₒ, for any prescribed geometry.