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The determination of the elastic field of an ellipsoidal inclusion in an anisotropic medium

Published online by Cambridge University Press:  24 October 2008

L. J. Walpole
Affiliation:
University of East Anglia, Norwich

Extract

1. Introduction. In studying the elastic behaviour of inhomogeneous systems certain inclusion and inhomogeneity problems are fundamental. In the ‘transformation problem’, a region (the ‘inclusion’) of an unbounded homogeneous anisotropic elastic medium would undergo some prescribed infinitesimal uniform strain (because of some spontaneous change in its shape) if it were not for the constraint imposed by the surrounding matrix. When the inclusion has an ellipsoidal shape, Eshelby (3, 4) was able to show that the stress and strain fields within the constrained inclusion are uniform and that calculations could be completed when the medium was isotropic. A generally anisotropic medium seemed to raise forbidding analyses, but Eshelby (3) did point the way to an evaluation of the uniform strain which several authors (referred to later) developed into an expression amenable to numerical computation. Here we offer an elementary and immediate route to this expression of the uniform strain, which has been accessible hitherto only by the circuitous procedures of Fourier transforms. It is available as soon as the uniform state of strain in the inclusion is perceived and before an alternative evaluation is commenced. First, we appeal to a theorem (not it seems previously known) which reveals (in particular) the vanishing of the mean strain in the infinitesimally thin ellipsoidal homoeoid lying just outside the inclusion. Secondly, we need only reflect that at each point of the interface there is an immediate algebraic expression of the strain just outside the inclusion in terms of the uniform strain just inside.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1977

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References

REFERENCES

(1)Bilby, B. A., Eshelby, J. D. and Kundu, A. K.The change of shape of a viscous ellipsoidal region embedded in a slowly deforming matrix having a different viscosity. Tectonophysics 28 (1975), 265274.CrossRefGoogle Scholar
(2)Eshelby, J. D.The force on an elastic singularity. Philos. Trans. Roy. Soc. London Ser. A 244 (1951), 87112.Google Scholar
(3)Eshelby, J. D.The determination of the elastic field of an ellipsoidal inclusion and related problems. Proc. Roy. Soc. Ser. A 241 (1957), 376396.Google Scholar
(4)Eshelby, J. D. Elastic inclusions and inhomogeneities. Progress in solid mechanics, vol. 2, chap. III (North Holland Publishing Co., Amsterdam, 1961).Google Scholar
(5)Gubernatis, J. E. and Krumhansl, J. A.Macroscopic engineering properties of polycrystalline materials: elastic properties. J. Appl. Phys. 46 (1975), 18751883.CrossRefGoogle Scholar
(6)Hill, R. Discontinuity relations in mechanics of solids. Progress in solid mechanics, vol. 2, chap. vi (North Holland Publishing Co., Amsterdam, 1961).Google Scholar
(7)Hill, R.Continuum micro-mechanics of elastoplastic polycrystals. J. Mech. Phys. Solids 13 (1965), 89101.CrossRefGoogle Scholar
(8)Hill, R.A self-consistent mechanics of composite materials. J. Mech. Phys. Solids 13 (1965), 213222.CrossRefGoogle Scholar
(9)Hill, R. An invariant treatment of interfacial discontinuities in elastic composites. In Continuum mechanics and related problems of analysis, pp. 597604 (Moscow, 1972).Google Scholar
(10)Hutchinson, J. W.Elastic-plastic behaviour of polycrystalline metals and composites. Proc. Roy. Soc. Ser. A 319, (1970), 247272.Google Scholar
(11)Hutchinson, J. W.Bounds and self-consistent estimates for creep of polycrystalline materials. Proc. Roy. Soc. Ser. A 348 (1976), 101127.Google Scholar
(12)Kinoshita, N. and Mura, T.Elastic fields of inclusions in anisotropic media. Phys. Statua Solidi. (A) 5 (1971), 759768.CrossRefGoogle Scholar
(13)Kneer, G.Über die Berechnung der Elastizitätsmoduln vielkristalliner Aggregate mit Textur. Phys. Status Solidi 9 (1965), 825838.CrossRefGoogle Scholar
(14)Kröner, E.Berechnung der elastischen Konstanten des Vielkristalls aus den Konstanten des Einkristalls. Z. Physik 151 (1958), 504518.CrossRefGoogle Scholar
(15)Kunin, I. A. and Sosnina, E. G.Stress concentration on an ellipsoidal inhomogeneity in an anisotropic elastic medium. J. Appl. Math. Mech. 37 (1973), 287296.CrossRefGoogle Scholar
(16)Kunin, I. A., Mirenkova, G. N. and Sosnina, E. G.An ellipsoidal crack and needle in an anisotropic elastic medium. J. Appl: Math. Mech. 37 (1973), 501508.Google Scholar
(17)Laws, N.On interfacial discontinuities in elastic composites. J. Elasticity 5 (1975), 227235.CrossRefGoogle Scholar
(18)Laws, N.The determination of stress and strain concentrations at an ellipsoidal inclusion in an anisotropic material. J. Elasticity (in press).Google Scholar
(19)Lin, S. C. and Mura, T.Elastic fields of inclusions in anisotropic media. Phys. Statua Solidi (A) 15,(1973), 281285.CrossRefGoogle Scholar
(20)Morris, P. R.Elastic constants of polycrystals. Internat. J. Engrg. Sci. 8 (1970), 4961.CrossRefGoogle Scholar
(21)Routh, E. J.Analytical statics, vol. II, 2nd edition (University Press, Cambridge, 1902).Google Scholar
(22)Russel, W. B.On the effective moduli of composite materials: effect of fiber length and geometry at dilute concentrations. Z. Angew. Math. Phys. 24 (1973), 581600.CrossRefGoogle Scholar
(23)Synge, J. L.The hypercircle in mathematical physics (University Press, Cambridge, 1957).CrossRefGoogle Scholar
(24)Thomson, W. and Tait, P. G.Treatise on natural philosophy, Part II (University Press, Cambridge, 1879).Google Scholar
(25)Walpole, L. J.The elastic field of an inclusion in an anisotropic medium. Proc. R. Soc. Ser. A 300 (1967), 270289.Google Scholar
(26)Willis, J. R. Ellipsoidal inclusion problems in anisotropic media. Private communication, 1964.Google Scholar