Imperfect Interface

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Kang Yong Lee - One of the best experts on this subject based on the ideXlab platform.

  • effect of an Imperfect Interface on the sh wave propagating in a cylindrical piezoelectric sensor
    Ultrasonics, 2010
    Co-Authors: Kang Yong Lee
    Abstract:

    Under harsh in situ conditions, the Interface in piezoelectric sensors may be damaged mechanically and/or electrically. The damaged Interface would in turn affect the electromechanical behaviors of the sensors. The purpose of the present work is to study the effect of the Imperfect Interface on SH wave propagating in a cylindrical piezoelectric sensor. The dispersion relations of SH wave are derived analytically and the phase velocity are obtained numerically. Parametric studies on the phase velocity indicate that the mechanical Imperfection may reduce the phase velocity under certain circumstances; however, the electrical Imperfection has no obvious effect on the phase velocity in any cases; with the thickness of the piezoelectric layer increasing, the phase velocity may increase, decrease or keep unchanged, depending on the combination of the values of the wave number and the mechanical Imperfection parameter.

  • interaction between an electrically permeable crack and the Imperfect Interface in a functionally graded piezoelectric sensor
    International Journal of Engineering Science, 2009
    Co-Authors: Kang Yong Lee
    Abstract:

    For a cracked piezoelectric sensor with an Imperfect Interface, the interaction between the crack and the Imperfect Interface is a problem of practical significance. Such a problem is investigated by the method of singular integral equation in the present work. The Interface is assumed to be mechanically compliant and weakly conducting. Parametric studies on stress intensity factors (SIFs) indicate that when the crack is near to the Interface SIFs increase as the Interface change from perfection to Imperfection, and the mechanical Imperfection generally has more remarkable influence on SIFs than the dielectric Imperfection does. For a crack in the piezoelectric layer and near to the Interface, the SIF gets less sensitive to the variation of the substrate thickness if the Interface becomes Imperfect. The interfacial Imperfection has less influence on the fracture behavior of a stiffer piezoelectric layer.

  • Analysis of a mode-I crack perpendicular to an Imperfect Interface
    International Journal of Solids and Structures, 2009
    Co-Authors: Xian Ci Zhong, Kang Yong Lee
    Abstract:

    The elastostatic problem of a mode-I crack embedded in a bimaterial with an Imperfect Interface is investigated. The crack is in proximity to and perpendicular to the Imperfect Interface, which is governed by linear spring-like relations. The Fourier transform is applied to reduce the associated mixed-boundary value problem to a singular integral equation with Cauchy kernel. By numerically solving the resulting equation, stress intensity factors near both crack tips are evaluated. Obtained results reveal that the stress intensity factors in the presence of the Imperfect Interface vary between that with a perfect Interface and that with a completely debonding Interface. Moreover, an increase in the Interface parameters decreases the stress intensity factors. In particular, when crack approaches to the weakened Interface closer, the stress intensity factors become larger for a sliding Interface, and become larger or smaller for a Winkler Interface, depending on the crack lying in a stiffer or softer material. The influences of the Imperfection of the Interface on the stress intensity factors for a bimaterial composed of aluminum and steel are presented graphically.

  • Crack tip shielding and anti-shielding effects of the Imperfect Interface in a layered piezoelectric sensor
    International Journal of Solids and Structures, 2009
    Co-Authors: Kang Yong Lee
    Abstract:

    AbstractThe purpose of the present work is to study the effect of an Imperfect Interface on the fracture behavior of a layered piezoelectric sensor. For mathematical convenience, the problem is investigated under mode III-a simple case in fracture mechanics. Fracture analysis is performed by the methods of Fourier integral transform and Cauchy singular integral equation. Parametric studies on the numerical results of energy release rate reveal the crack tip shielding and anti-shielding effects of the Imperfect Interface. When the inclined angle of crack is less than 0.1π, the Imperfect Interface may shield the crack, however, when it is larger than 0.2π, the crack may be anti-shielded. If the distance between a crack tip and the Imperfect Interface is less than two times of the crack length, the shielding or anti-shielding effect is remarkable, and otherwise it is negligible. Finally, the crack tip shielding and anti-shielding effects of the mechanical Imperfection are generally more remarkable than those of the dielectric Imperfection

  • The shielding effect of the Imperfect Interface on a mode III permeable crack in a layered piezoelectric sensor
    Engineering Fracture Mechanics, 2009
    Co-Authors: Kang Yong Lee
    Abstract:

    The mechanical model is established for a piezoelectric sensor with a mode III permeable crack parallel to the Imperfect Interface. Fracture analysis is performed by the standard methods of Fourier transform and singular integral equation. Three conclusions are drawn: (a) the Imperfect Interface has a shielding effect on the crack parallel and very near to it; (b) the shielding effect depends on the structural stiffness and the distance between the crack and Interface; (c) for the electrically permeable crack, mechanical Imperfection has more remarkable shielding effect than dielectric Imperfection does.

Peter Schiavone - One of the best experts on this subject based on the ideXlab platform.

  • neutrality of an elliptical inhomogeneity in finite plane elastostatics of harmonic materials
    Mathematics and Mechanics of Solids, 2017
    Co-Authors: Xu Wang, Peter Schiavone
    Abstract:

    We examine the neutrality of an elliptical inhomogeneity embedded in a particular class of compressible hyperelastic materials of harmonic type when a uniform Piola stress field is prescribed in the surrounding matrix. The present method is based on a spring-type Imperfect Interface model and on the proper choice of Imperfect Interface function, which realizes the same degree of Imperfection in both normal and tangential directions. The analysis indicates that, in general, the neutral shape and the single Imperfect Interface function are both dependent on the magnitude of the prescribed stress field.

  • a circular inhomogeneity with a mixed type Imperfect Interface in anti plane shear
    Applied Mathematical Modelling, 2017
    Co-Authors: Xu Wang, Peter Schiavone
    Abstract:

    Abstract We present a rigorous study of the problem associated with a circular inhomogeneity embedded in an infinite matrix subjected to anti-plane shear deformations. The inhomogeneity and the matrix are each endowed with separate and distinct surface elasticities and are bonded together through a soft spring-type Imperfect interphase layer. This combination is referred to in the literature as a ‘mixed-type Imperfect Interface’ due to the fact that the soft interphase layer (described by the spring model) is bounded by two stiff Interfaces arising from the separate surface elasticities of the inhomogeneity and the matrix. The entire composite is subjected to remote shear stresses and we allow for the presence of a screw dislocation in either the inhomogeneity or the matrix. The corresponding boundary value problem is reduced to two coupled second-order differential equations for the two analytic functions defined in the two phases (as well as their analytical continuations) leading to solutions in either series or closed-form. The analysis indicates that the stress field in the composite and the image force acting on the screw dislocation can be described completely in terms of three size-dependent parameters and a size-independent mismatch parameter. Interestingly, in the absence of the screw dislocation, the size-dependent stress field inside the inhomogeneity is uniform. Several numerical examples are presented to demonstrate the solution for a screw dislocation located inside the matrix. The results show that it is permissible for the dislocation to have multiple equilibrium positions.

  • interaction between an edge dislocation and a circular inhomogeneity with a mixed type Imperfect Interface
    Archive of Applied Mechanics, 2017
    Co-Authors: Xu Wang, Peter Schiavone
    Abstract:

    We present an analytical solution (in series form) to the plane strain problem associated with an edge dislocation in the vicinity of a circular elastic inhomogeneity with a ‘mixed-type Imperfect Interface.’ The latter is a representation of the interfacial region in which the inhomogeneity and the matrix are endowed with separate and distinct Gurtin–Murdoch surface elasticities and bonded together through a spring-type Imperfect Interface. The coefficients in the resulting series solution are determined in a rather elegant manner requiring only the inverse of a number of 4\(\times \)4 real symmetric positive definite matrices. The stress distribution in the composite structure and the normalized image force acting on the edge dislocation are found to be dependent on six size-dependent dimensionless parameters, among which four arise from the associated surface elasticities and two from the linear spring model of the Interface. Asymptotic expressions for the image force when the dislocation is located at a remote distance from the inhomogeneity are also obtained analytically. The correctness of the solution is verified both numerically and analytically by comparison with existing results in the literature. Most importantly, our numerical results indicate that it is possible to find multiple equilibrium positions for the edge dislocation.

  • A circular inhomogeneity with mixed-type Imperfect Interface under in-plane deformations
    International Journal of Mechanics and Materials in Design, 2016
    Co-Authors: Xu Wang, Peter Schiavone
    Abstract:

    We investigate the in-plane deformations of a circular inhomogeneity bonded to an infinite matrix through a mixed-type Imperfect Interface when the matrix is subjected to remote uniform stresses. The inhomogeneity and the matrix are endowed with separate and distinct Gurtin–Murdoch surface elasticities yet bonded together through a spring-type Imperfect Interface. This arrangement in which a soft Interface (represented by the spring model) is bounded by two stiff Interfaces (from the surface elasticities) is referred to as a ‘mixed-type Imperfect Interface’. A closed-form solution to the corresponding deformation problem is obtained via the use of complex variable methods, in particular, analytic continuation. We show that the introduction of the mixed-type Imperfect Interface leads to stress distributions in the composite which depend on six size-dependent parameters. In particular, the stress distribution inside the inhomogeneity is shown to be generally non-uniform except when a particular condition (which we identify explicitly) is satisfied by the material parameters, in which case the internal (size-dependent) stress distribution is uniform for any uniform remote loading. Finally, our solution is used to study the design of neutral and harmonic elastic inhomogeneities.

  • uniform strain field inside a non circular inhomogeneity with homogeneously Imperfect Interface in anisotropic anti plane shear
    Zeitschrift für Angewandte Mathematik und Physik, 2016
    Co-Authors: Peter Schiavone, Ming Dai, Cunfa Gao
    Abstract:

    We re-examine the conclusion established earlier in the literature that in the presence of a homogeneously Imperfect Interface, the circular inhomogeneity is the only shape of inhomogeneity which can achieve a uniform internal strain field in an isotropic or anisotropic material subjected to anti-plane shear. We show that under certain conditions, it is indeed possible to design such non-circular inhomogeneities despite the limitation of a homogeneously Imperfect Interface. Our method proceeds by prescribing a uniform strain field inside a non-circular inhomogeneity via perturbations of the uniform strain field inside the analogous circular inhomogeneity and then subsequently identifying the corresponding (non-circular) shape via the use of a conformal mapping whose unknown coefficients are determined from a system of nonlinear equations. We illustrate our results with several examples. We note also that, for a given size of inhomogeneity, the minimum value of the Interface parameter required to guarantee the desired uniform internal strain increases as the elastic constants of the inclusion approach those of the matrix. Finally, we discuss in detail the relationship between the curvature of the Interface and the displacement jump across the Interface in the design of such inhomogeneities.

Serge Dumont - One of the best experts on this subject based on the ideXlab platform.

  • An asymptotic derivation of a general Imperfect Interface law for linear multiphysics composites
    International Journal of Solids and Structures, 2019
    Co-Authors: R. Rizzoni, Frederic Lebon, M. Serpilli, Serge Dumont
    Abstract:

    The paper is concerned with the derivation of a general Imperfect Interface law in a linear multiphysics framework for a composite, constituted by two solids, separated by a thin adhesive layer. The analysis is performed by means of the asymptotic expansions technique. After defining a small parameter ε, which will tend to zero, associated with the thickness and the constitutive coefficients of the intermediate layer, we characterize three different limit models and their associated limit problems: the soft Interface model, in which the constitutive coefficients depend linearly on ε; the hard Interface model, in which the constitutive properties are independent of ε; the rigid Interface model, in which they depend on 1 ε. The asymptotic expansion method is reviewed by taking into account the effect of higher order terms and by defining a general multiphysics Interface law which comprises the above aforementioned models.

  • an asymptotic derivation of a general Imperfect Interface law for linear multiphysics composites
    International Journal of Solids and Structures, 2019
    Co-Authors: R. Rizzoni, Frederic Lebon, M. Serpilli, Serge Dumont
    Abstract:

    Abstract The paper is concerned with the derivation of a general Imperfect Interface law in a linear multiphysics framework for a composite, constituted by two solids, separated by a thin adhesive layer. The analysis is performed by means of the asymptotic expansions technique. After defining a small parameter e, which will tend to zero, associated with the thickness and the constitutive coefficients of the intermediate layer, we characterize three different limit models and their associated limit problems: the soft Interface model, in which the constitutive coefficients depend linearly on e; the hard Interface model, in which the constitutive properties are independent of e; the rigid Interface model, in which they depend on 1 e . The asymptotic expansion method is reviewed by taking into account the effect of higher order terms and by defining a general multiphysics Interface law which comprises the above aforementioned models.

Yuantian Huang - One of the best experts on this subject based on the ideXlab platform.

  • shear waves guided by the Imperfect Interface of two magnetoelectric materials
    Ultrasonics, 2010
    Co-Authors: Yuantian Huang
    Abstract:

    In this paper, propagation of shear waves along a weak Interface of two dissimilar magnetoelectric or magnetoelectroelastic materials is considered. Two exact dispersion relations are obtained for an Imperfect electrode Interface and an unelectroded Interface, respectively. The existence condition of the interfacial waves is studied. Our results show that the interfacial Imperfection strongly affects the velocity of the interfacial shear waves. In particular, for certain bi-magnetoelectric material, the interfacial shear waves may do not exist for a perfect Interface and exist only for an Imperfect Interface. These findings are useful for the design of high-frequency wave devices.

  • interfacial shear horizontal sh waves propagating in a two phase piezoelectric piezomagnetic structure with an Imperfect Interface
    Philosophical Magazine Letters, 2009
    Co-Authors: Yuantian Huang, K Y Lee
    Abstract:

    Shear waves propagating along the Imperfectly bonded Interface of a magnetoelectric composite consisting of Piezoelectric (PE) and Piezomagnetic (PM) phases are considered. An exact dispersion relation is obtained. It is found that the interfacial Imperfection strongly affects the velocity of interfacial shear waves. The existence condition of the interfacial shear waves is derived. In particular, for certain combined magnetoelectric composites, interfacial shear waves do no exist for perfect Interface and exist only for Imperfect Interface. Moreover, the corresponding waves are dispersive, and the range of the phase velocity is derived, lying between the smaller of the Bleustein-Gulyaev waves of two PE and PM materials and the interfacial waves for the perfect bonding. These findings are useful for PE/PM composites in the microwave technology.

  • interfacial shear horizontal sh waves propagating in a two phase piezoelectric piezomagnetic structure with an Imperfect Interface
    Philosophical Magazine Letters, 2009
    Co-Authors: Yuantian Huang, Xianfang Li
    Abstract:

    Shear waves propagating along the Imperfectly bonded Interface of a magnetoelectric composite consisting of Piezoelectric (PE) and Piezomagnetic (PM) phases are considered. An exact dispersion relation is obtained. It is found that the interfacial Imperfection strongly affects the velocity of interfacial shear waves. The existence condition of the interfacial shear waves is derived. In particular, for certain combined magnetoelectric composites, interfacial shear waves do no exist for perfect Interface and exist only for Imperfect Interface. Moreover, the corresponding waves are dispersive, and the range of the phase velocity is derived, lying between the smaller of the Bleustein-Gulyaev waves of two PE and PM materials and the interfacial waves for the perfect bonding. These findings are useful for PE/PM composites in the microwave technology.

Frederic Lebon - One of the best experts on this subject based on the ideXlab platform.

  • An asymptotic derivation of a general Imperfect Interface law for linear multiphysics composites
    International Journal of Solids and Structures, 2019
    Co-Authors: R. Rizzoni, Frederic Lebon, M. Serpilli, Serge Dumont
    Abstract:

    The paper is concerned with the derivation of a general Imperfect Interface law in a linear multiphysics framework for a composite, constituted by two solids, separated by a thin adhesive layer. The analysis is performed by means of the asymptotic expansions technique. After defining a small parameter ε, which will tend to zero, associated with the thickness and the constitutive coefficients of the intermediate layer, we characterize three different limit models and their associated limit problems: the soft Interface model, in which the constitutive coefficients depend linearly on ε; the hard Interface model, in which the constitutive properties are independent of ε; the rigid Interface model, in which they depend on 1 ε. The asymptotic expansion method is reviewed by taking into account the effect of higher order terms and by defining a general multiphysics Interface law which comprises the above aforementioned models.

  • an asymptotic derivation of a general Imperfect Interface law for linear multiphysics composites
    International Journal of Solids and Structures, 2019
    Co-Authors: R. Rizzoni, Frederic Lebon, M. Serpilli, Serge Dumont
    Abstract:

    Abstract The paper is concerned with the derivation of a general Imperfect Interface law in a linear multiphysics framework for a composite, constituted by two solids, separated by a thin adhesive layer. The analysis is performed by means of the asymptotic expansions technique. After defining a small parameter e, which will tend to zero, associated with the thickness and the constitutive coefficients of the intermediate layer, we characterize three different limit models and their associated limit problems: the soft Interface model, in which the constitutive coefficients depend linearly on e; the hard Interface model, in which the constitutive properties are independent of e; the rigid Interface model, in which they depend on 1 e . The asymptotic expansion method is reviewed by taking into account the effect of higher order terms and by defining a general multiphysics Interface law which comprises the above aforementioned models.

  • Derivation of Imperfect Interface models coupling damage and temperature
    Computers and Mathematics with Applications, 2019
    Co-Authors: Elena Bonetti, Giovanna Bonfanti, Frederic Lebon
    Abstract:

    In this paper we introduce a model describing a layered structure composed by two thermoelastic adherents and a thin adhesive subject to a degradation process. By an asymptotic expansion method, we derive a model of Imperfect Interface coupling damage and temperature evolution. Moreover, assuming that the behaviour of the adhesive is ruled by two different regimes, one in traction and one in compression, we derive a second limit model where unilateral contact conditions on the Interface are also included.

  • Derivation of a model of Imperfect Interface with finite strains and damage by asymptotic techniques: an application to masonry structures
    Meccanica, 2018
    Co-Authors: Maria Letizia Raffa, Frederic Lebon, R. Rizzoni
    Abstract:

    The proposed study aims to derive an Imperfect Interface model which couples finite strain and damaging. The governing equations are obtained via an asymptotic approach within the finite strain theory. Theoretical findings have been numerically validated within an original application to brick/mortar Interfaces in masonry walls in shear loading conditions.

  • a model of Imperfect Interface with damage
    Meccanica, 2017
    Co-Authors: Elena Bonetti, Giovanna Bonfanti, Frederic Lebon, Raffaella Rizzoni
    Abstract:

    In this paper two models of damaged materials are presented. The first one describes a structure composed by two adherents and an adhesive which is micro-cracked and subject to two different regimes, one in traction and one in compression. The second model is a model of Interface derived from the first one through an asymptotic analysis, and it can be interpreted as a model for contact with adhesion and unilateral constraint. Simple numerical examples are presented.