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Title: An optimum approximation of n-point correlation functions of random heterogeneous material systems

Journal Article · · Journal of Chemical Physics
DOI:https://doi.org/10.1063/1.4865966· OSTI ID:22255086
;  [1];  [2];  [3];  [3]
  1. Aerospace Engineering Department, University of Illinois, 104 S Wright St., Urbana, Illinois 61801 (United States)
  2. School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive N.W., Atlanta, Georgia 30332-0245 (United States)
  3. University of Strasbourg, ICube/CNRS, 2 Rue Boussingault, 67000 Strasbourg (France)

An approximate solution for n-point correlation functions is developed in this study. In the approximate solution, weight functions are used to connect subsets of (n-1)-point correlation functions to estimate the full set of n-point correlation functions. In previous related studies, simple weight functions were introduced for the approximation of three and four-point correlation functions. In this work, the general framework of the weight functions is extended and derived to achieve optimum accuracy for approximate n-point correlation functions. Such approximation can be utilized to construct global n-point correlation functions for a system when there exist limited information about these functions in a subset of space. To verify its accuracy, the new formulation is used to approximate numerically three-point correlation functions from the set of two-point functions directly evaluated from a virtually generated isotropic heterogeneous microstructure representing a particulate composite system. Similarly, three-point functions are approximated for an anisotropic glass fiber/epoxy composite system and compared to their corresponding reference values calculated from an experimental dataset acquired by computational tomography. Results from both virtual and experimental studies confirm the accuracy of the new approximation. The new formulation can be utilized to attain a more accurate approximation to global n-point correlation functions for heterogeneous material systems with a hierarchy of length scales.

OSTI ID:
22255086
Journal Information:
Journal of Chemical Physics, Vol. 140, Issue 7; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
Country of Publication:
United States
Language:
English