Size-dependent interaction of an edge dislocation with an elliptical nano-inhomogeneity incorporating interface effects

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:49

Article

Shodja, H. M.^1,2  Ahmadzadeh-Bakhshayesh, H.¹  Gutkin, M. Yu.^3,4,5 

[1] Sharif Univ Technol, Dept Civil Engn, Tehran 111559313, Iran

[2] Sharif Univ Technol, Inst Nanosci & Nanotechnol, Tehran 111559161, Iran

[3] Russian Acad Sci, Inst Problems Mech Engn, St Petersburg 199178, Russia

[4] Sr Petersburg State Polytech Univ, Dept Phys Mat Strength & Plast, St Petersburg 195251, Russia

[5] St Petersburg State Univ, Dept Theory Elast, St Petersburg 198504, Russia

关键词: Interface stress;    Elliptical inhomogeneity;    Edge dislocation;    Nano scale;   

DOI  :  10.1016/j.ijsolstr.2011.11.013

来源: Elsevier

【 摘 要 】

The elastic behavior of an edge dislocation, which is positioned outside of a nanoscale elliptical inhomogeneity, is studied within the interface elasticity approach incorporating the elastic moduli and surface tension of the interface. The complex potential function method is used. The dislocation stress field and the image force acting on the dislocation are found and analyzed in detail. The difference between the solutions obtained within the classical-elasticity and interface-elasticity approaches is discussed. It is shown that for the stress field, this difference can be significant in those points of the inhomogeneity-matrix interface, where the radius of curvature is smaller and which are closer to the dislocation. For the image force, this difference can be considerable or dispensable in dependence on the dislocation position, its Burgers vector orientation, and relations between the elastic moduli of the matrix, inhomogeneity and their interface. Under some special conditions, the dislocation can occupy a stable equilibrium position in atomically close vicinity of the interface. The size effect is demonstrated that the normalized image force strongly depends on the inhomogeneity size when it is in the range of several tens of nanometers, in contrast with the classical solution where this force is always constant. The general issue is that the interface elasticity effects become more evident when the characteristic sizes of the problem (inhomogeneity size, interface curvature radius and dislocation-interface spacing) reduce to the nanoscale. (C) 2011 Elsevier Ltd. All rights reserved.

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