In this paper,the mechanical response of a one-dimensional(1D)hexagonal piezoelectric quasicrystal(PQC)thin film is analyzed under electric and temperature loads.Based on the Euler-Bernoulli beam theory,a theoretical ...In this paper,the mechanical response of a one-dimensional(1D)hexagonal piezoelectric quasicrystal(PQC)thin film is analyzed under electric and temperature loads.Based on the Euler-Bernoulli beam theory,a theoretical model is proposed,resulting in coupled governing integral equations that account for interfacial normal and shear stresses.To numerically solve these integral equations,an expansion method using orthogonal Chebyshev polynomials is employed.The results provide insights into the interfacial stresses,axial force,as well as axial and vertical deformations of the PQC film.Additionally,fracture criteria,including stress intensity factors,mode angles,and the J-integral,are evaluated.The solution is compared with the membrane theory,neglecting the normal stress and bending deformation.Finally,the effects of stiffness and aspect ratio on the PQC film are thoroughly discussed.This study serves as a valuable guide for controlling the mechanical response and conducting safety assessments of PQC film systems.展开更多
The interaction between a screw dislocation and an elliptical hole with two asymmetrical cracks in a one-dimensional(1 D) hexagonal quasicrystal with piezoelectric effect is considered. A general formula of the genera...The interaction between a screw dislocation and an elliptical hole with two asymmetrical cracks in a one-dimensional(1 D) hexagonal quasicrystal with piezoelectric effect is considered. A general formula of the generalized stress field, the field intensity factor, and the image force is derived, and the special cases are discussed. Several numerical examples are given to show the effects of the material properties and the dislocation position on the field intensity factors and the image forces.展开更多
The explicit expression of Eshelby tensors for one-dimensional(1D) hexagonal quasicrystal composites is presented by using Green’s function method. The closed forms of Eshelby tensors in the special cases of spheroid...The explicit expression of Eshelby tensors for one-dimensional(1D) hexagonal quasicrystal composites is presented by using Green’s function method. The closed forms of Eshelby tensors in the special cases of spheroid, elliptic cylinder, ribbon-like,penny-shaped, and rod-shaped inclusions embedded in 1 D hexagonal quasicrystal matrices are given. As an application of Eshelby tensors, the analytical expressions for the effective properties of the 1 D hexagonal quasicrystal composites are derived based on the Mori-Tanaka method. The effects of the volume fraction of the inclusion on the elastic properties of the composite materials are discussed.展开更多
The present work is concerned with a penny-shaped Dugdale crack embedded in an infinite space of one-dimensional （1D） hexagonal quasicrystals and subjected to two identical axisymmetric temperature loadings on the u...The present work is concerned with a penny-shaped Dugdale crack embedded in an infinite space of one-dimensional （1D） hexagonal quasicrystals and subjected to two identical axisymmetric temperature loadings on the upper and lower crack surfaces. Applying Dugdale hypothesis to thermo-elastic results, the extent of the plastic zone at the crack tip is determined. The normal stress outside the plastic zone and crack surface displacement are derived in terms of special functions. For a uniform loading case, the corresponding results are presented by simpli- fying the preceding results. Numerical calculations are carried out to show the influence of some parameters.展开更多
In this paper,we investigate the interfacial behavior of a thin one-dimensional(1D)hexagonal quasicrystal(QC)film bonded on an elastic substrate subjected to a mismatch strain due to thermal variation.The contact inte...In this paper,we investigate the interfacial behavior of a thin one-dimensional(1D)hexagonal quasicrystal(QC)film bonded on an elastic substrate subjected to a mismatch strain due to thermal variation.The contact interface is assumed to be nonslipping,with both perfectly bonded and debonded boundary conditions.The Fourier transform technique is adopted to establish the integral equations in terms of interfacial shear stress,which are solved as a linear algebraic system by approximating the unknown phonon interfacial shear stress via the series expansion of the Chebyshev polynomials.The expressions are explicitly obtained for the phonon interfacial shear stress,internal normal stress,and stress intensity factors(SIFs).Finally,based on numerical calculations,we briefly discuss the effects of the material mismatch,the geometry of the QC film,and the debonded length and location on stresses and SIFs.展开更多
In this paper, the three-dimensional(3D) interfacial fracture is analyzed in a one-dimensional(1D) hexagonal quasicrystal(QC) coating structure under mechanical loading. A planar interface crack with arbitrary shape i...In this paper, the three-dimensional(3D) interfacial fracture is analyzed in a one-dimensional(1D) hexagonal quasicrystal(QC) coating structure under mechanical loading. A planar interface crack with arbitrary shape is studied by a displacement discontinuity method. Fundamental solutions of interfacial concentrated displacement discontinuities are obtained by the Hankel transform technique, and the corresponding boundary integral-differential equations are constructed with the superposition principle.Green’s functions of constant interfacial displacement discontinuities within a rectangular element are derived, and a boundary element method is proposed for numerical simulation.The singularity of stresses near the crack front is investigated, and the stress intensity factors(SIFs) as well as energy release rates(ERRs) are determined. Finally, relevant influencing factors on the fracture behavior are discussed.展开更多
In this paper,we investigate the interfacial behavior of a thin,penny-shaped,one-dimensional(1D)hexagonal functionally graded(FG)piezoelectric quasicrystal(PQC)film bonded on a temperature-dependent elastic substrate ...In this paper,we investigate the interfacial behavior of a thin,penny-shaped,one-dimensional(1D)hexagonal functionally graded(FG)piezoelectric quasicrystal(PQC)film bonded on a temperature-dependent elastic substrate under thermal and electrical loads.The problem is modeled as axisymmetric based on the membrane theory,with the peeling stress and bending moment being disregarded.A potential theory method,combined with the Hankel transform technique,is utilized to derive the displacement field on the substrate surface.With perfect interfacial bonding assumption,an integral equation governing the phonon interfacial shear stress is formulated and numerically solved by the Chebyshev polynomials.Explicit expressions are derived for the interfacial shear stress,the internal stresses within the PQC film and the substrate,the axial strain,and the stress intensity factors(SIFs).Numerical simulations are conducted to investigate the effects of the film's aspect ratio,material inhomogeneity,material mismatch,and temperature-dependent material properties on its mechanical response.The results provide insights for the functional design and reliability assessment of FG PQC film/substrate systems.展开更多
基金Supported by the National Natural Science Foundation of China (Nos. 11902293 and 12272353)。
文摘In this paper,the mechanical response of a one-dimensional(1D)hexagonal piezoelectric quasicrystal(PQC)thin film is analyzed under electric and temperature loads.Based on the Euler-Bernoulli beam theory,a theoretical model is proposed,resulting in coupled governing integral equations that account for interfacial normal and shear stresses.To numerically solve these integral equations,an expansion method using orthogonal Chebyshev polynomials is employed.The results provide insights into the interfacial stresses,axial force,as well as axial and vertical deformations of the PQC film.Additionally,fracture criteria,including stress intensity factors,mode angles,and the J-integral,are evaluated.The solution is compared with the membrane theory,neglecting the normal stress and bending deformation.Finally,the effects of stiffness and aspect ratio on the PQC film are thoroughly discussed.This study serves as a valuable guide for controlling the mechanical response and conducting safety assessments of PQC film systems.
基金Project supported by the National Natural Science Foundation of China(Nos.11962026,11462020,11862021,and 11502123)the Inner Mongolia Natural Science Foundation of China(Nos.2017MS0104 and NJZY18022)。
文摘The interaction between a screw dislocation and an elliptical hole with two asymmetrical cracks in a one-dimensional(1 D) hexagonal quasicrystal with piezoelectric effect is considered. A general formula of the generalized stress field, the field intensity factor, and the image force is derived, and the special cases are discussed. Several numerical examples are given to show the effects of the material properties and the dislocation position on the field intensity factors and the image forces.
基金the National Natural Science Foundation of China(Nos.11962026,12002175,12162027,and 62161045)the Inner Mongolia Natural Science Foundation of China(No.2020MS01018)。
文摘The explicit expression of Eshelby tensors for one-dimensional(1D) hexagonal quasicrystal composites is presented by using Green’s function method. The closed forms of Eshelby tensors in the special cases of spheroid, elliptic cylinder, ribbon-like,penny-shaped, and rod-shaped inclusions embedded in 1 D hexagonal quasicrystal matrices are given. As an application of Eshelby tensors, the analytical expressions for the effective properties of the 1 D hexagonal quasicrystal composites are derived based on the Mori-Tanaka method. The effects of the volume fraction of the inclusion on the elastic properties of the composite materials are discussed.
基金supported by the National Natural Science Foundation of China(No.11102171)Program for New Century Excellent Talents in University of Ministry of Education of China(NCET-13-0973)+1 种基金The support from Sichuan Provincial Youth Science and Technology Innovation Team(2013-TD-0004)Scientific Research Foundation for Returned Scholars(Ministry of Education of China)are acknowledged as well
文摘The present work is concerned with a penny-shaped Dugdale crack embedded in an infinite space of one-dimensional （1D） hexagonal quasicrystals and subjected to two identical axisymmetric temperature loadings on the upper and lower crack surfaces. Applying Dugdale hypothesis to thermo-elastic results, the extent of the plastic zone at the crack tip is determined. The normal stress outside the plastic zone and crack surface displacement are derived in terms of special functions. For a uniform loading case, the corresponding results are presented by simpli- fying the preceding results. Numerical calculations are carried out to show the influence of some parameters.
基金Project supported by the National Natural Science Foundation of China(Nos.11572289,1171407,11702252,and 11902293)the China Postdoctoral Science Foundation(No.2019M652563)。
文摘In this paper,we investigate the interfacial behavior of a thin one-dimensional(1D)hexagonal quasicrystal(QC)film bonded on an elastic substrate subjected to a mismatch strain due to thermal variation.The contact interface is assumed to be nonslipping,with both perfectly bonded and debonded boundary conditions.The Fourier transform technique is adopted to establish the integral equations in terms of interfacial shear stress,which are solved as a linear algebraic system by approximating the unknown phonon interfacial shear stress via the series expansion of the Chebyshev polynomials.The expressions are explicitly obtained for the phonon interfacial shear stress,internal normal stress,and stress intensity factors(SIFs).Finally,based on numerical calculations,we briefly discuss the effects of the material mismatch,the geometry of the QC film,and the debonded length and location on stresses and SIFs.
基金Project supported by the National Natural Science Foundation of China (Nos. 11572289, 1171407,11702252, and 11902293)the China Postdoctoral Science Foundation (No. 2019M652563)。
文摘In this paper, the three-dimensional(3D) interfacial fracture is analyzed in a one-dimensional(1D) hexagonal quasicrystal(QC) coating structure under mechanical loading. A planar interface crack with arbitrary shape is studied by a displacement discontinuity method. Fundamental solutions of interfacial concentrated displacement discontinuities are obtained by the Hankel transform technique, and the corresponding boundary integral-differential equations are constructed with the superposition principle.Green’s functions of constant interfacial displacement discontinuities within a rectangular element are derived, and a boundary element method is proposed for numerical simulation.The singularity of stresses near the crack front is investigated, and the stress intensity factors(SIFs) as well as energy release rates(ERRs) are determined. Finally, relevant influencing factors on the fracture behavior are discussed.
基金Project supported by the National Natural Science Foundation of China(Nos.11902293 and 12272353)。
文摘In this paper,we investigate the interfacial behavior of a thin,penny-shaped,one-dimensional(1D)hexagonal functionally graded(FG)piezoelectric quasicrystal(PQC)film bonded on a temperature-dependent elastic substrate under thermal and electrical loads.The problem is modeled as axisymmetric based on the membrane theory,with the peeling stress and bending moment being disregarded.A potential theory method,combined with the Hankel transform technique,is utilized to derive the displacement field on the substrate surface.With perfect interfacial bonding assumption,an integral equation governing the phonon interfacial shear stress is formulated and numerically solved by the Chebyshev polynomials.Explicit expressions are derived for the interfacial shear stress,the internal stresses within the PQC film and the substrate,the axial strain,and the stress intensity factors(SIFs).Numerical simulations are conducted to investigate the effects of the film's aspect ratio,material inhomogeneity,material mismatch,and temperature-dependent material properties on its mechanical response.The results provide insights for the functional design and reliability assessment of FG PQC film/substrate systems.
