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**Search for:**surface-interface-effects

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#### Surface/interface effect on the scattering of Love waves by a nano-size surface-breaking crack within an ultra-thin layer bonded to an elastic half-space

, Article International Journal of Solids and Structures ; Volume 108 , 2017 , Pages 63-73 ; 00207683 (ISSN) ; Ghafarollahi, A ; Enzevaee, C ; Sharif University of Technology
Abstract

Using the mathematical framework of surface/interface elasticity theory, an analytical solution is presented for the antiplane scattering of Love waves by a surface-breaking crack normal to the free surface of an ultra-thin layer bonded to a semi-infinite medium. Fourier transform technique is used to formulate the corresponding mixed-boundary value problem as a singular integral equation of Cauchy type. Within the context of the present theory, the scattered stress field, the Mode III dynamic stress intensity factor (DSIF) at the crack-tip, and the reflection coefficient at large distances from the crack face are computed and plotted for different wave numbers and surface/interface...

#### Surface/interface effects on the formation of misfit dislocation in a core-shell nanowire

, Article Philosophical Magazine ; Volume 94, Issue 5 , 11 February , 2014 , Pages 492-519 ; ISSN: 14786435 ; Gutkin, M. Y ; Shodja, H. M ; Sharif University of Technology
Abstract

The misfit strain within the core of a two-phase free-standing core-shell nanowire resulting in the generation of an edge misfit dislocation or an edge misfit dislocation dipole at the core-shell interface is considered theoretically within both the classical and surface/interface elasticity approaches. The critical conditions for the misfit dislocation generation are studied and discussed in detail with special attention to the non-classical surface/interface effect. It is shown that this effect is significant for fine cores of radius smaller than roughly 20 interatomic distances. The positive and negative surface/interface Lamé constants mostly make the generation of the misfit dislocation...

#### Surface/interface effects on elastic behavior of an edge dislocation in the shell of a core-shell nanowire

, Article European Journal of Mechanics, A/Solids ; Volume 41 , September–October , 2013 , Pages 86-100 ; 09977538 (ISSN) ; Rezazadeh Kalehbasti, S ; Shodja, H. M ; Sharif University of Technology
2013

Abstract

The elastic behavior of an edge dislocation placed in the shell of a free-standing core-shell nanowire is considered within the theory of surface/interface elasticity. Using the method of complex potential functions the expressions for the stress field of the dislocation, image forces on the dislocation, and the dislocation strain energy are derived and studied in detail. A special attention is paid to non-classical effects revealed within the surface/interface elasticity approach where a characteristic length parameter referred to as surface/interface modulus is introduced. These effects are (i) the stress oscillations along the shell surface and core-shell interface for negative values of...

#### Axisymmetric response of a bi-material full-space reinforced by an interfacial thin film

, Article International Journal of Solids and Structures ; Volume 90 , July , 2016 , Pages 251–260 ; 00207683 (ISSN) ; Samea, P ; Eskandari, M ; Sharif University of Technology
Elsevier Ltd
2016

Abstract

Analytical treatment of a linear elastic isotropic bi-material full-space reinforced by an interfacial thin film under axisymmetric normal loading is addressed. The thin film is modeled as an extensible membrane perfectly bonded to the half-spaces. By virtue of Love's potential function and Hankel integral transform, elastic fields of the system are explicitly written in the form of semi-infinite line integrals. The analytical results are verified by the special cases corresponding to the surface stiffened half-space and classical bi-material problem. The limiting cases of reinforced homogeneous full-space and inextensible membrane are presented and discussed. The proposed formulation is...

#### Torsional surface wave propagation in a transversely isotropic FG substrate with piezoelectric over-layer within surface/interface theory

, Article Acta Mechanica ; Volume 231, Issue 6 , 2020 , Pages 2203-2216 ; Mohamadi Shodja, H ; Sharif University of Technology
Springer
2020

Abstract

Propagation of the torsional surface waves in a medium consisting of a functionally graded (FG) substrate bonded to a thin piezoelectric over-layer has been analytically formulated in the mathematical framework of surface/interface elasticity theory. In the cases where the wavelength and/or the thickness of the over-layer are comparable to the surface/interface characteristic length, then the surface/interface effects are not negligible. It is assumed that the over-layer is made of hexagonal 622 crystals with a single axis of rotational symmetry coinciding with the axis of polarization. The half-space is made of an FG transversely isotropic material in which the elasticity tensor and the...

#### Axisymmetric circular indentation of a half-space reinforced by a buried elastic thin film

, Article Mathematics and Mechanics of Solids ; Vol. 19, issue. 6 , 2014 , p. 703-712 ; Eskandari, M ; Sharif University of Technology
Abstract

The analytical treatment of an axisymmetric rigid punch indentation of an isotropic half-space reinforced by a buried extensible thin film is addressed. With the aid of appropriate displacement potential functions, Hankel transforms, and some mathematical techniques, the mixed boundary value problem under consideration is reduced to a Fredholm integral equation of the second kind. The most interesting results of the problem, including the equivalent normal stiffness of the system and the contact stress distribution beneath the rigid punch, are expressed in terms of the solution of the obtained Fredholm integral equation. Some limiting cases corresponding to inextensible and extremely...

#### Exact diffusion-induced elastic fields of a spherical core-shell nano-electrode li-ion battery via spectral theory

, Article Journal of the Electrochemical Society ; Volume 167, Issue 13 , 2020 ; Shahryari, B ; Azizi, P ; Roumi, F ; Sharif University of Technology
IOP Publishing Ltd
2020

Abstract

In Li-ion batteries the interface between the nano-size spherical core graphite and its surrounding solid electrolyte interphase (SEI) layer, just inside SEI is susceptible to damage. Thus, accurate determination of the associated elastic fields is one of the challenges in optimizing the lifetime and capacity of Li-ion batteries. The required precision is achieved by considering the core graphite which belongs to the crystal class D6h as homogeneous spherically isotropic and SEI layer as functionally graded (FG) isotropic material. Moreover, to account for the surface/interface effects appropriately the core-shell nano-structure subjected to the diffusion-induced time-dependent nonuniform...

#### Surface/interface effect on the propagation of high-frequency SH surface waves in an ultra-thin FGP over-layer bonded to a substrate

, Article Acta Mechanica ; Volume 232, Issue 12 , 2021 , Pages 4677-4689 ; 00015970 (ISSN) ; Shodja, H. M ; Sharif University of Technology
Springer
2021

Abstract

Shear horizontal surface acoustic waves (SAW) propagation in an ultra-thin functionally graded piezoelectric (FGP) layer bonded to a homogeneous substrate is analytically formulated in the mathematical framework of surface/interface elasticity theory. It is assumed that the FGP over-layer is made of a hexagonal 6-mm crystal with a single axis of rotational symmetry coinciding with the axis of polarization. The mechanical and piezoelectric properties of the layer are assumed to vary linearly with thickness. The half-space is made of a transversely isotropic material. It should be mentioned that this model is of great interest in investigating SAW devices at high frequencies. Accounting for...