TY - JOUR
T1 - On diagonal and elastic symmetry of the approximate effective stiffness tensor of heterogeneous media
AU - Benveniste, Y.
AU - Dvorak, G. J.
AU - Chen, T.
N1 - Funding Information:
Funding for this work was provided, in part, by the ONR/DARPA-HiTASC programa t Rensselaera, nd by the Air Force Officeo f ScientificR esearch.
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1991
Y1 - 1991
N2 - The existence of diagonal symmetry in estimates of overall stiffness tensors of heterogeneous media is examined for several micromechanical models. The dilute approximation gives symmetric estimates for all matrix-based multiphase media. The Mori-Tanaka and the self-consistent methods do so for all two-phase systems, but only for those multiphase systems where the dispersed inclusions have a similar shape and alignment. However, the differential schemes associated with the self-consistent method can predict diagonally symmetric overall stiffness and compliance for multiphase systems of arbitrary phase geometry. A related question is raised about the equivalence of two possible approaches to evaluation of the overall thermal stress and strain tensors. A direct estimate follows from each of the above models, whereas Levin's results [Mechanics of Solids 2, 58 (1967)] permit an indirect evaluation in terms of the estimated overall mechanical properties or concentration factors and phase thermoelastic moduli. These two results are shown to coincide for those systems and models which return diagonally symmetric estimates of the overall stiffness. Finally, model predictions of the overall elastic symmetry of composite media are discussed with regard to the spatial distribution of the phases.
AB - The existence of diagonal symmetry in estimates of overall stiffness tensors of heterogeneous media is examined for several micromechanical models. The dilute approximation gives symmetric estimates for all matrix-based multiphase media. The Mori-Tanaka and the self-consistent methods do so for all two-phase systems, but only for those multiphase systems where the dispersed inclusions have a similar shape and alignment. However, the differential schemes associated with the self-consistent method can predict diagonally symmetric overall stiffness and compliance for multiphase systems of arbitrary phase geometry. A related question is raised about the equivalence of two possible approaches to evaluation of the overall thermal stress and strain tensors. A direct estimate follows from each of the above models, whereas Levin's results [Mechanics of Solids 2, 58 (1967)] permit an indirect evaluation in terms of the estimated overall mechanical properties or concentration factors and phase thermoelastic moduli. These two results are shown to coincide for those systems and models which return diagonally symmetric estimates of the overall stiffness. Finally, model predictions of the overall elastic symmetry of composite media are discussed with regard to the spatial distribution of the phases.
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U2 - 10.1016/0022-5096(91)90012-D
DO - 10.1016/0022-5096(91)90012-D
M3 - Article
AN - SCOPUS:44949280260
SN - 0022-5096
VL - 39
SP - 927
EP - 946
JO - Journal of the Mechanics and Physics of Solids
JF - Journal of the Mechanics and Physics of Solids
IS - 7
ER -