Showing papers by "Yue-Sheng Wang published in 2014"
TL;DR: In this article, the free vibration of magnetoelectro-elastic (MEE) nanoplates is investigated based on the nonlocal theory and Kirchhoff plate theory.
Abstract: In this paper, the free vibration of magnetoelectro-elastic (MEE) nanoplates is investigated based on the nonlocal theory and Kirchhoff plate theory. The MEE nanoplate is assumed as all edges simply supported rectangular plate subjected to the biaxial force, external electric potential, external magnetic potential, and temperature rise. By using the Hamilton's principle, the governing equations and boundary conditions are derived and then solved analytically to obtain the natural frequencies of MEE nanoplates. A parametric study is presented to examine the effect of the nonlocal parameter, thermo-magneto-electro-mechanical loadings and aspect ratio on the vibration characteristics of MEE nanoplates. It is found that the natural frequency is quite sensitive to the mechanical loading, electric loading and magnetic loading, while it is insensitive to the thermal loading.
195 citations
TL;DR: In this paper, the free vibration of magneto-electro-elastic (MEE) nanobeams based on the nonlocal theory and Timoshenko beam theory is investigated.
Abstract: This paper investigates the free vibration of magneto-electro-elastic (MEE) nanobeams based on the nonlocal theory and Timoshenko beam theory. The MEE nanobeam is subjected to the external electric potential, magnetic potential and uniform temperature rise. The governing equations and boundary conditions are derived by using the Hamilton principle and discretized by using the differential quadrature (DQ) method to determine the natural frequencies and mode shapes. A detailed parametric study is conducted to study the influences of the nonlocal parameter, temperature rise, external electric and magnetic potentials on the size-dependent vibration characteristics of MEE nanobeams.
156 citations
TL;DR: In this paper, the authors used the finite element method and a coarse-to-fine two-stage genetic algorithm as the forward calculation method and the inverse search scheme, respectively, to perform both the unconstrained and constrained optimal design of the unit cell topology of two-dimensional square-latticed solid phononic crystals (PnCs), to maximize the relative widths of the gaps between the adjacent energy bands of the PnCs.
Abstract: By using the finite element method and a "coarse to fine" two-stage genetic algorithm as the forward calculation method and the inverse search scheme, respectively, we perform both the unconstrained and constrained optimal design of the unit cell topology of the two-dimensional square-latticed solid phononic crystals (PnCs), to maximize the relative widths of the gaps between the adjacent energy bands of the PnCs. In the constrained optimizations, the maximization is subjected to the constraint of a predefined average density. In the numerical results, the variation patterns of the optimized structures with the order of the bandgap for both the out-plane shear and the in-plane mixed elastic wave modes are presented, and the effects of both the material contrast and the predefined average density on the obtained optimal structures are discussed.
140 citations
TL;DR: In this article, an analytical solution for the simply supported piezoelectric nanoshell by representing displacement components in the double Fourier series was given for a simply supported PNE, and the differential quadrature method was employed to obtain numerical solutions of PNEs under various boundary conditions.
140 citations
TL;DR: Based on the nonlocal Love's shell theory, an embedded magneto-electro-elastic (MEE) cylindrical nanoshell model incorporating effects of the small scale parameter and thermo-electron-magnetic loadings was developed in this article.
Abstract: Based on the nonlocal Love's shell theory, this paper develops an embedded magneto-electro-elastic (MEE) cylindrical nanoshell model. This model incorporates effects of the small scale parameter and thermo-electro-magnetic loadings. The surrounding elastic medium is described as the Winkler model characterized by the spring. By using this model and the Hamilton principle, the governing equations and boundary conditions are derived for free vibration of the embedded MEE cylindrical nanoshells. The Navier's method is first utilized to obtain the analytical solution for the simply supported MEE nanoshell. Then, numerical solutions for MEE nanoshells under various boundary conditions are obtained by using the differential quadrature (DQ) method. A detailed parametric study is conducted to highlight the influences of the nonlocal parameter, temperature rise, external electric potential, external magnetic potential, spring constant, radius-to-thickness ratio and length-to-radius ratio on natural frequencies of MEE nanoshells.
113 citations
TL;DR: In this article, the authors used the non-dominated sorting-based genetic algorithm II to design two-dimensional (2D) porous phononic crystals (PnCs) with a simultaneously maximal bandgap width (BGW) and the minimal mass through multi-objective optimization.
Abstract: In this paper, we show that it is possible to design two-dimensional (2D) porous phononic crystals (PnCs) with a simultaneously maximal bandgap width (BGW) and the minimal mass through multi-objective optimization (MOOP) by using the non-dominated sorting-based genetic algorithm II. Compared with the single-objective optimization, the optimized structures from the MOOP can achieve a balance between the relative BGW and mass of PnCs. For the combined out-of-plane and in-plane wave modes, we present an optimized design with the relatively big BGW, which breaks the record value of 2D porous PnCs.
81 citations
TL;DR: In this paper, the axisymmetric postbuckling of functionally graded material (FGM) annular microplates based on the modified couple stress theory, Mindlin plate theory and von Karman geometric nonlinearity was investigated.
79 citations
TL;DR: In this paper, a classification of band-gaps in layered phononic crystals is proposed based on the analysis of the eigenvalues of the transfer matrix for a unit-cell and the asymptotics derived for the transmission coefficient.
77 citations
TL;DR: In this paper, the adaptive fuzzy fitness granulation (AFFG) was used to design the phononic crystals with large relative bandgap width (BGW) for combined out-of-plane and in-plane wave modes.
72 citations
TL;DR: In this paper, the buckling and post-buckling behaviors of piezoelectric nanobeams were investigated by using the nonlocal Timoshenko beam theory and von Karman geometric nonlinearity.
Abstract: Buckling and post-buckling behaviors of piezoelectric nanobeams are investigated by using the nonlocal Timoshenko beam theory and von Karman geometric nonlinearity. The piezoelectric nanobeam is subjected to an axial compression force, an applied voltage and a uniform temperature rise. After constructing the energy functionals, the nonlinear governing equations are derived by using the principle of minimum total potential energy and discretized by using the differential quadrature (DQ) method. A direct iterative method is employed to determine the buckling and post-buckling responses of piezoelectric nanobeams with hinged-hinged, clamped-hinged and clamped-clamped end conditions. Numerical examples are presented to study the influences of the nonlocal parameter, temperature rise and external electric voltage on the size-dependent buckling and post-buckling responses of piezoelectric nanobeams.
71 citations
TL;DR: In this paper, the two-dimensional frictionless contact problem of a functionally graded magneto-electro-elastic materials (FGMEEMs) layered halfplane under a rigid flat or a cylindrical punch was investigated.
TL;DR: In this article, the effects of the geometry parameters of the 2D-zigzag lattices on the bandgaps are investigated and discussed, and the mechanism of the bandgap generation is analyzed by studying the vibration modes at the band gap edges.
Abstract: In this paper we propose some kinds of two-dimensional square zigzag lattice structures and study their bandgaps and directional propagation of elastic waves. The band structures and the transmission spectra of the systems are calculated by using the finite element method. The effects of the geometry parameters of the 2d-zigzag lattices on the bandgaps are investigated and discussed. The mechanism of the bandgap generation is analyzed by studying the vibration modes at the bandgap edges. Multiple wide complete bandgaps are found in a wide porosity range owing to the separation of the degeneracy by introducing bending arms. The bandgaps are sensitive to the geometry parameters of the systems. The deformed displacement fields of the transient response of finite structures subjected to harmonic loads are presented to show the directional wave propagation. The research work in this paper is relevant to the practical design of cellular structures with enhanced vibro-acoustics performance.
TL;DR: In this paper, the residual magnetic field signals of ferromagnets under the plastic deformation were calculated by calculating the contour maps of tangential and normal RMF gradients, and the 3D effect was discussed.
TL;DR: In this paper, an alternative coating profile with a comblike profile is proposed and investigated and the band structures are calculated using the finite element method, and it is shown that a complete bandgap can be induced at a significantly low frequency, the wavelength of which is more than 20 times the lattice constant.
Abstract: Two-dimensional ternary locally resonant phononic crystals can be used for vibration control and noise insulation in the low (even audible) frequency range. They traditionally consist of cylindrical scatterers with uniform coatings in their exterior. An alternative coating profile with a comblike profile is proposed and investigated in this paper. The band structures are calculated using the finite element method. We find that a complete bandgap can be induced at a significantly low frequency, the wavelength of which is more than 20 times the lattice constant. The mechanism for such a change is suggested using an equivalent spring–mass model and analyzing the eigenmodes at the bandgap edges. Numerical results and the results predicted by the spring–mass model are coherent.
TL;DR: In this article, a detailed discussion on the variation of the photonic and phononic bandgaps with the geometry and lattice form of the structure of a two-dimensional phoxonic crystal with veins in square, triangle and honeycomb lattices is presented.
TL;DR: A phoxonic crystal hetero-structure cavity is proposed, which can simultaneously confine surface acoustic and optical waves and show obvious shifts in eigenfrequencies of the photonic cavity mode modes induced by different phononic cavity modes.
Abstract: Phoxonic crystal is a promising material for manipulating sound and light simultaneously. In this paper, we theoretically demonstrate the propagation of acoustic and optical waves along the truncated surface of a two-dimensional square-latticed phoxonic crystal. Further, a phoxonic crystal hetero-structure cavity is proposed, which can simultaneously confine surface acoustic and optical waves. The interface motion and photoelastic effects are taken into account in the acousto-optical coupling. The results show obvious shifts in eigenfrequencies of the photonic cavity modes induced by different phononic cavity modes. The symmetry of the phononic cavity modes plays a more important role in the single-phonon exchange process than in the case of the multi-phonon exchange. Under the same deformation, the frequency shift of the photonic transverse electric mode is larger than that of the transverse magnetic mode.
TL;DR: In this article, the topology optimization of 2D phoxonic crystals with simultaneously maximal and complete photonic and phononic bandgaps was studied by using the non-nominated sorting-based genetic algorithm II.
Abstract: By using the nondominated sorting-based genetic algorithm II, we study the topology optimization of 2D phoxonic crystals (PxC) with simultaneously maximal and complete photonic and phononic bandgaps. Our results show that the optimized structures are composed of solid lumps with narrow connections, and their Pareto-optimal solution set can keep a balance between photonic and phononic bandgap widths. Moreover, we investigate the localized states of PxC based on the optimized structure and obtain structures with more effectively multimodal photon and phonon localization. The presented structures with highly focused energy are good choices for PxC sensors. For practical application, we design a simple structure with smooth edges based on the optimized structure. It is shown that the designed simple structure has similar properties to the optimized structure, i.e., simultaneous wide phononic and photonic bandgaps and a highly effective phononic/photonic cavity.
TL;DR: By using the finite element method, the propagation of Lamb waves in a sandwich plate with a periodic composite core was investigated in this article, where the composite core is constituted by a square array of...
Abstract: By using the finite element method, the propagation of Lamb waves in a sandwich plate with a periodic composite core is investigated. The periodic composite core is constituted by a square array of...
TL;DR: In this article, the effects of the geometry parameters of the 2D-zigzag lattices on the bandgaps are investigated and discussed, and the mechanism of the bandgap generation is analyzed by studying the vibration modes at the band gap edges.
Abstract: In this paper we propose various types of two-dimensional (2D) square zigzag lattice structures, and we study their bandgaps and directional propagation of elastic waves. The band structures and the transmission spectra of the systems are calculated by using the finite element method. The effects of the geometry parameters of the 2D-zigzag lattices on the bandgaps are investigated and discussed. The mechanism of the bandgap generation is analyzed by studying the vibration modes at the bandgap edges. Multiple wide complete bandgaps are found in a wide porosity range owing to the separation of the degeneracy by introducing bending arms. The bandgaps are sensitive to the geometry parameters of the systems. The deformed displacement fields of the transient response of finite structures subjected to time-harmonic loads are presented to show the directional wave propagation. The research in this paper is relevant to the practical design of cellular structures with enhanced vibro-acoustics performance.
TL;DR: In this article, a combined theoretical, numerical and experimental study of acoustic wave propagation in 1D locally resonant phononic crystals made of acoustic resonators grafted onto a waveguide is presented.
Abstract: In this paper, we present a combined theoretical, numerical and experimental study of acoustic wave propagation in 1D locally resonant phononic crystals made of acoustic resonators grafted onto a waveguide. The case of one single resonator grafted onto the waveguide is first investigated and a model of transmission cancellation at resonant frequencies is obtained. The model includes the excitation of evanescent guided waves attached to the grafting points. When extended to periodical arrays of grafted resonators, the model provides us with a definite theoretical expression for the complex band structure. Comparison with experimental results and complex band structures obtained by numerical simulation suggests a strong dependence of transmission through the crystal on the lattice constant of the grafted resonators. It is found that evanescent waves in the waveguide play a key role when the lattice constant is in the sub-wavelength range.
TL;DR: In this article, the authors investigated the thermoelastic contact instability of a functionally graded material (FGM) layer and a homogeneous halfplane using the perturbation method.
TL;DR: In this article, 3Y-ZrO 2 /(3Y − ZrO2 + Ni) sandwich ceramics were fabricated through cold isostatic pressing and pressureless sintering.
TL;DR: In this article, the authors investigated the two-dimensional sliding frictional contact of a piezoelectric halfplane in the plane strain state under the action of a rigid flat or a triangular punch.
TL;DR: In this paper, a criterion for deformation twinning is derived by considering the elastic lattice-rotation strain, and the result tested against molecular dynamics simulations of magnesium and titanium single crystals.
Abstract: Twinning is generally considered to be the primary deformation mechanism for hexagonal close-packed (hcp) metals due to their limited slip systems. Recent microcompression experiments point to strong size effects indicating that pyramidal slips can dominate in deformation under compression. We present analysis on the twinnability of an ideal hcp single crystal at the nanoscale. A criterion for deformation twinning is derived by considering the elastic lattice-rotation strain, and the result tested against molecular dynamics simulations of magnesium and titanium single crystals. We find ⟨c + a⟩ pyramidal slip dominates the compression deformation at the nanoscale, which is consistent with experimental observations on microcompression. This analysis gives an interpretation of size effects in deformation twinning, at the same time it provides an explanation for the so-called strength differential effect.
TL;DR: In this paper, four kinds of two-dimensional square beam-like zigzag lattice structures and their bandgaps and directional propagation of elastic waves are calculated by using the finite element method.
Abstract: In this paper we propose four kinds of two-dimensional square beam-like zigzag lattice structures and study their bandgaps and directional propagation of elastic waves. The band structures are calculated by using the finite element method. Both the in-plane and out-of-plane waves are investigated simultaneously via the three-dimensional Euler beam elements. The mechanism of the bandgap generation is analyzed by studying the vibration modes at the bandgap edges. The effects of the geometry parameters of the xy- and z-zigzag lattices on the bandgaps are investigated and discussed. Multiple complete bandgaps are found owing to the separation of the degeneracy by introducing bending arms. The bandgaps are sensitive to the geometry parameters of the periodic systems. The deformed displacement fields of the harmonic responses of a finite lattice structure subjected to harmonic loads at different positions are illustrated to show the directional wave propagation. An extension of the proposed concept to the hexagonal lattices is also presented. The research work in this paper is relevant to the practical design of cellular structures with enhanced vibro-acoustics performance.
01 Jan 2014
TL;DR: In this paper, the deformation behaviors in magnesium single crystal under the c-axis tension and compression are investigated by molecular dynamics simulations, and it is shown that the pyramidal slip dominates under compression loading.
Abstract: The dominant deformation mode at low temperatures in magnesium and its alloys is generally regarded to be twinning because of the hcp crystal structure. More recently, the phenomenon of a “loss” of twins has been reported in microcompression experiments on magnesium single crystals, while significant plasticity and hardening occurred due to six active pyramidal slip systems. These results pointed to an intriguing deformation pattern of magnesium single crystal at the nanoscale, namely no deformation twins are present in the microcompression deformed specimens. In this work, the deformation behaviors in magnesium single crystal under the c-axis tension and compression are investigated by molecular dynamics simulations. Under c-axis tension at low temperature, twinning is indeed found to be the main deformation mechanisms, which are consistent with the related experimental results. However, simulations of c-axis compression show that the pyramidal slip dominates under compression loading. No compression twins are observed in simulations at different temperatures for different loading and boundary conditions. This is explained by an analysis of the lattice structure of twins in pure magnesium, revealing that the change of the strain energy caused by the lattice rotation may play a more important role on the plastic deformation mechanisms at the nanoscale. Our theoretical and simulation results provide a unifying interpretation of recent microcompression experiments on magnesium (0001) single crystals.
TL;DR: In this paper, the authors theoretically investigate the phononic and photonic guided modes in the three-dimensional topology-type PXCs with a line defect, and they show that both elastic and optical energies can be highly confined in and near the defect region.
Abstract: Phoxonic crystals (PXCs) which exhibit simultaneous phononic and photonic bandgaps are promising artificial materials for optomechanical and acousto-optical devices. In this paper, we theoretically investigate the phononic and photonic guided modes in the three-dimensional topology-type PXCs with a line defect. By varying the geometrical parameters, simultaneous guidance of the slow elastic and light (electromagnetic) waves can be realized. Both elastic and optical energies can be highly confined in and near the defect region. Small elastic and optical group velocities with small group velocity dispersions can be achieved. The group velocities are about 10 and 20 times smaller than the transverse velocity of the elastic waves in silicon and the speed of light in vacuum, respectively.
TL;DR: In this article, the Dirichlet-to-Neumann map method is employed to compute the band structures of two-dimensional phononic crystals with smoothly sliding connection conditions between the matrix and the scatterers, which are composed of square or triangular lattices of circular solid cylinders in a solid matrix.
Abstract: In the present paper, the Dirichlet-to-Neumann map method is employed to compute the band structures of two-dimensional phononic crystals with smoothly sliding connection conditions between the matrix and the scatterers, which are composed of square or triangular lattices of circular solid cylinders in a solid matrix. The solid/solid systems of various material parameters with sliding interface conditions are considered. The influence of sliding interface conditions on the band structures is analyzed and discussed. The results show that the smoothly sliding interface condition has significant effect on the band structure.
TL;DR: In this paper, the stability of an elastic solid sliding against a functionally graded material (FGM) coated half-plane is investigated by examining the resilience of elastic waves caused by the perturbation.
TL;DR: In this article, the phase composition and microstructure of TiAl/NiCoCrAl microlaminated sheet have been analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscope (TEM).