ORCID Profile
0000-0003-1117-9619
Current Organisation
Central South University
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Publisher: Elsevier BV
Date: 06-2009
Publisher: Springer Science and Business Media LLC
Date: 12-06-2007
Publisher: Informa UK Limited
Date: 05-2009
Publisher: Elsevier BV
Date: 2013
Publisher: American Institute of Aeronautics and Astronautics (AIAA)
Date: 04-2011
DOI: 10.2514/1.J050572
Publisher: IOP Publishing
Date: 04-2014
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2011
Publisher: Informa UK Limited
Date: 04-2011
Publisher: Elsevier BV
Date: 09-2016
DOI: 10.1016/J.ULTRAS.2016.05.021
Abstract: Trapped modes in a hard cylindrical tube with a local axisymmetric enlargement or bulge and filled with a uniform acoustic medium is studied. The governing Helmholtz equation in the cylindrical coordinate system is employed to deal with this problem through the domain decomposition method and matching technique. The trapped modes and the corresponding frequencies less than the threshold frequency or cut-off frequency are derived. It is found that in addition to the fundamental mode, the second- and higher-order trapped modes exist and depend on the geometry parameters of the local bulge. The effects of the bulge radius and width on the frequencies are discussed. The local bulge leads to a decrease of the frequencies and the corresponding vibration mode is localized near the bulge. A multimodal analysis is made and frequency band gap of generalized trapped modes is also studied. A frequency band gap depends on the radius of a bulge and is independent of its width. The obtained results can be extended to analyze bound states in quantum wires.
Publisher: Elsevier BV
Date: 12-2019
Publisher: Springer Science and Business Media LLC
Date: 21-10-2008
Publisher: Elsevier BV
Date: 08-2012
Publisher: Elsevier BV
Date: 07-2000
Publisher: Elsevier BV
Date: 09-2006
Publisher: Elsevier BV
Date: 07-2023
Publisher: Elsevier BV
Date: 07-2009
Publisher: Wiley
Date: 14-12-2016
Publisher: Informa UK Limited
Date: 18-05-2021
Publisher: World Scientific Pub Co Pte Lt
Date: 10-2018
DOI: 10.1142/S0219455418501183
Abstract: Structural stability of a double-nanowire system with surface effects subjected to axial compressive forces is analyzed. Taking into account the Casimir force between the two nanowires, two coupled governing equations for buckling of a double-nanowire system are derived. For four typical end supports including simply-supported, cl ed, cantilevered, and cl ed-pinned double-nanowire systems, the characteristic equations are derived and the critical loads are determined for the out-of-phase in-plane buckling. Numerical results indicate that positive surface elasticity enhances the load-carrying capacity of the nanowires, and the reverse is also true. The Casimir force and residual surface tension always increase the critical loads.
Publisher: Trans Tech Publications, Ltd.
Date: 2012
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMM.152-154.1417
Abstract: Using the nonlocal elasticity theory, this paper presents a static analysis of a microbeam according to the Timoshenko beam model. A fourth-order governing differential equation is derived and a general solution is suggested. For a cantilever beam at nanoscale subjected to uniform distributed loading, explicit expressions for deflection, rotation and strain energy are obtained. The nonlocal effect decreases the deflection and maximum stress distribution. With a double cantilever beam model, the strain energy release rate of a cracked beam is evaluated, and the results obtained show that the strain energy release rate is decreased (hence an increased apparent fracture toughness is measured) when the beam thickness is several times the material characteristic length. However, in the absence of a uniformly distributed loading, the nonlocal beam theory fails to account for the size-dependent properties for static analysis. Particularly, the nonlocal Euler-Bernoulli beam can be analytically obtained from the nonlocal Timoshenko beam if the apparent shear modulus is sufficiently large.
Publisher: Elsevier BV
Date: 03-2014
Publisher: Springer Science and Business Media LLC
Date: 12-07-2006
Publisher: Elsevier BV
Date: 06-2015
Publisher: Elsevier BV
Date: 11-2013
Publisher: Elsevier BV
Date: 2015
Publisher: IOP Publishing
Date: 12-12-2006
Publisher: Elsevier BV
Date: 03-2003
Publisher: Springer Science and Business Media LLC
Date: 07-02-2012
Publisher: Elsevier BV
Date: 2013
Publisher: IOP Publishing
Date: 04-1998
Publisher: Springer Science and Business Media LLC
Date: 27-02-2020
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 08-2015
Publisher: SAGE Publications
Date: 24-03-2017
Abstract: Bending of an annular thick plate resting on a ring support is analyzed under the action of power-law axisymmetric loading. A single governing differential equation for the Mindlin plate theory is derived. By solving associated boundary value problem, the optimal support location is determined to achieve minimizing the maximum deflection of a moderately thick circular or annular plate. The minimum sag of a heavy solid circular plate with or without the center support under self-weight is also analyzed. In addition to applied loading and the restraint of plate's rims, the optimal location of the ring support is also related to Poisson's ratio and the ratio of inner-to-outer radius. Auxetic plates with negative Poisson's ratio require larger ring support's radius, and conventional plates require smaller ring support's radius. Usually, the optimal support location is closer to the outer rim and far to the inner rim for a plate of self-weight. The obtained results are useful in safety design of circular or annular plates under complicated loading.
Publisher: Elsevier BV
Date: 06-2019
Publisher: Elsevier BV
Date: 11-2006
Publisher: World Scientific Pub Co Pte Lt
Date: 05-03-2018
DOI: 10.1142/S0217984918500951
Abstract: This paper studies transverse vibration of nanoscale cantilevered and bridged sensors carrying a nanoparticle. The nanoscale sensors are modelled as Euler–Bernoulli beams with surface effect and nanoparticle as a concentrated mass. Frequency equations of cantilevered and bridged beam-mass system are derived and exact resonance frequencies are calculated. An alternative Fredholm integral equation method is used to obtain an approximate explicit expression for the fundamental frequency for both cases. A comparison between the approximate and analytical results is made and the approximation accuracy is satisfactory. The influences of the residual surface stress, surface elasticity, and attached mass on the resonance frequencies and mode shapes are discussed. These results are useful to illustrate the surface phenomena and are helpful to design micro-/nano-mechanical sensors.
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 12-2015
Publisher: SAGE Publications
Date: 09-2007
Abstract: The transient response of a semi-infinite transversely isotropic piezoceramic strip containing an edge crack is analysed for the case where electric excitation is suddenly exerted at the material end surface. The crack is assumed to be impermeable to electric field. Ahypersingular integral equation for crack-opening displacement (COD) is derived via solving the associated mixed initial-boundary-value problem and solved numerically based on a collocation technique. By performing a numerical inversion of Laplace transform, dynamic CODs are determined and illustrated graphically.
Publisher: Elsevier BV
Date: 04-2012
Publisher: Wiley
Date: 03-1999
DOI: 10.1002/(SICI)1521-3951(199903)212:1<19::AID-PSSB19>3.0.CO;2-O
Publisher: World Scientific Pub Co Pte Ltd
Date: 10-02-2008
DOI: 10.1142/S0217979208038648
Abstract: The mechanical properties of materials such as elastic modulus, hardness, and fracture toughness, can be measured by nanoindentation. For a thin film coated on an elastic substrate, the cross-sectional nanoindentation technique can decrease the influence of plastic deformation around the nanoindenter apex on fracture toughness for interface delamination. Considering the effect of the elastic substrate, the theory of an elastic beam bonded to an elastic foundation is further developed to obtain the energy release rate of interfacial debonding. Explicit closed-form solutions are determined, and the influence of the substrate on the energy release rate is shown graphically.
Publisher: Elsevier BV
Date: 11-2017
Publisher: Elsevier BV
Date: 07-2003
Publisher: Elsevier BV
Date: 02-2023
Publisher: Springer Science and Business Media LLC
Date: 03-2004
Publisher: SAGE Publications
Date: 21-04-2016
Abstract: Axial free vibration of a nanobar carrying a nanoparticle is studied based on the nonlocal elasticity theory and Love’s assumption. By considering inertia of radial motion during longitudinal vibration, a governing equation for a nanobar–mass oscillation system is derived via Hamilton’s principle. An exact frequency equation is obtained and an approximate simple expression for the fundamental-mode resonance frequency is given. The size effect of the resonance frequencies is elucidated. The classical Love bar theory and the nonlocal bar theory can be recovered from two special cases by setting the nonlocal parameter and Poisson’s ratio to zero, respectively. Numerical ex les are given to show the influence of the nonlocal scaling parameter and attached mass on the resonance frequencies and frequency shifts. Identification formulas for estimating the mass of an attached nanoparticle and predicting the nonlocal parameter are established through the frequency change.
Publisher: Informa UK Limited
Date: 09-2006
Publisher: Elsevier BV
Date: 05-2012
Publisher: Springer Science and Business Media LLC
Date: 03-02-2006
Publisher: Elsevier BV
Date: 12-2015
Publisher: Informa UK Limited
Date: 02-2009
Publisher: Elsevier BV
Date: 05-2010
Publisher: Elsevier BV
Date: 07-2019
Publisher: Springer Science and Business Media LLC
Date: 08-04-2009
Publisher: Elsevier BV
Date: 07-2003
Publisher: Informa UK Limited
Date: 03-2010
Publisher: Elsevier BV
Date: 11-2022
Publisher: SAGE Publications
Date: 09-2020
Abstract: The classical Fourier heat conduction theory as well as the widely used Fick’s diffusion law predicts an infinite wave velocity. This is physically unrealistic. By generalizing the classical Fourier’s and Fick’s laws, this paper presents a hyperbolic diffusion law to apply heat and moisture coupling. The transient response of the hygro-thermo-elastic field in infinitely long hollow cylinders subjected to sudden heat and moisture shock on the inner and outer surfaces is studied. With the aid of the Laplace transform and the decoupling technique, the closed-form solutions of temperature, moisture, elastic displacement and stresses are determined respectively. The analytical results show that the thermal and moisture relaxation time effect between temperature and moisture is significant for composites. Compared with the classic counterpart, the finite hygrothermal wave speed of the pipe is achieved and decreases with the relaxation time rising. The temperature, moisture, elastic displacement and stresses are calculated. Numerical results are displayed graphically to show the influence of the phase lag of heat/moisture flux on the response of the hygro-thermo-elastic fields. Non-Fourier and non-Fick effects are remarkable between the classic model and hyperbolic hygrothermal coupling model. Some drawbacks induced by the classical Fourier’s and Fick’s laws are averted.
Publisher: Elsevier BV
Date: 08-2010
Publisher: American Institute of Aeronautics and Astronautics (AIAA)
Date: 10-2023
DOI: 10.2514/1.T6772
Abstract: The transient temperature response of a bimaterial with a circular insulated interface region is studied under sudden heating or cooling. The time-fractional dual-phase-lag heat conduction model is adopted to simulate the non-Fourier effect. The problem is reduced to an initial-boundary value problem. The Laplace transform is applied to convert the problem to a mixed boundary value problem, and then the Hankel transform reduces it to a Fredholm integral equation. Special situations for asymptotic thermal behavior near the insulated circular edge and for the steady-state cases are discussed, respectively. The dynamic intensity factors of heat flux and temperature gradient near the insulated circular edge are computed numerically through Stehfest’s Laplace inversion transform technique. The influences of fractional order and relaxation times on the instantaneous temperature change are analyzed. The exact solution of temperature fields for the steady-state case is derived and displayed graphically. The wave-like diffusion behavior of the fractional dual-phase-lag model is interpreted.
Publisher: Elsevier BV
Date: 11-2018
Publisher: American Institute of Aeronautics and Astronautics (AIAA)
Date: 09-2009
DOI: 10.2514/1.41995
Publisher: American Society of Civil Engineers (ASCE)
Date: 2011
Publisher: ASME International
Date: 11-2003
DOI: 10.1115/1.1631593
Publisher: Springer Science and Business Media LLC
Date: 09-2008
Publisher: Elsevier BV
Date: 10-2011
Publisher: Elsevier BV
Date: 11-2021
Publisher: World Scientific Pub Co Pte Lt
Date: 30-10-2018
DOI: 10.1142/S0217984918503724
Abstract: Flexoelectricity describes the coupling between polarization and strain gradients and presents a strong size dependence at nanoscale. In the current work, based on the extended linear piezoelectricity theory with flexoelectricity, we study bending of piezoelectric beams with consideration of flexoelectric effect. When a concentrated force at any position and electric voltage is exerted, the expression for bending deflection of simply-supported and cl ed beams is derived. The obtained results show that flexoelectric effect can cause a softer elastic behavior of simply-supported and cl ed beams. Sensitivity analysis of the transverse deflection and bending moment is made for two typical boundary conditions. Flexoelectric effect has a more significant effect on the bending response of a piezoelectric beam with smaller thickness.
Publisher: Springer Science and Business Media LLC
Date: 10-2009
Publisher: Informa UK Limited
Date: 05-2010
Publisher: Elsevier BV
Date: 02-2015
Publisher: Elsevier BV
Date: 04-2010
Publisher: Royal Society of Chemistry (RSC)
Date: 1994
DOI: 10.1039/FT9949002047
Publisher: Springer Science and Business Media LLC
Date: 12-2010
Publisher: Elsevier BV
Date: 08-2022
Publisher: Elsevier BV
Date: 12-2006
Publisher: SAGE Publications
Date: 15-02-2007
Abstract: The electric and elastic behaviors of a piezoelectric actuator under an external electric input are analyzed. The actuator is composed of a piezoelectric ceramic plate with two penny-shaped thin electrodes at the opposite surfaces. The problem is solved by using the Hankel transform technique. By reducing the mixed boundary value problem to a Fredholm integral equation of the second kind, numerical results are presented for the mechanical response of the piezoelectric plate subjected to applied electric stimulus. The profiles of the elastic displacements and the distributions of the stresses for a PZT-5H plate are shown graphically. The results indicate that the vertical surface displacement arrives at a maximum at the electrode region, while the radial surface displacement arrives at a peak at the electrode edge. Moreover, elastic stresses arrive at their peaks near the electrode edge within the piezoelectric plate.
Publisher: Elsevier BV
Date: 10-2016
Publisher: AIP Publishing
Date: 15-01-2021
DOI: 10.1063/5.0032343
Abstract: Flexoelectricity is an electromechanical coupling phenomenon between polarization and strain gradient. Based on the Kirchhoff thin plate theory, the electromechanical coupling responses of nanoplates with the piezoelectric and flexoelectric effects are studied in this paper. Free vibration of a piezoelectric nanoplate with consideration of flexoelectricity is analyzed with emphasis on the influence of the dynamic flexoelectric effect on the natural frequencies. By means of Hamilton’s variational principle, the governing equation of rectangular plates together with associated boundary conditions is derived. The natural frequencies are evaluated for a nanoplate simply supported at two opposite edges, and exact frequency equations are obtained for the other two opposite edges being simply supported, cl ed–cl ed, cl ed–free, simply supported–free, or cl ed–simply supported. The influence of dynamic flexoelectricity on the natural frequencies is elucidated. The results show that the dynamic flexoelectric effect is also size-dependent the smaller the plate thickness is, the more obvious the dynamic flexoelectric effect is. The results also show that the dynamic flexoelectric effect is more pronounced when the order of vibration modes is higher and nanoplate’s side ratio is larger. The positive and negative choice of static and dynamic flexoelectric coefficients have completely different effects on the natural frequencies. The influence of the dynamic flexoelectric effect on the natural frequencies is closely related to the side constraint and geometry of the plate. The piezoelectric effect does not alter the natural frequencies for free vibration of a homogeneous nanoplate.
Publisher: Springer Science and Business Media LLC
Date: 27-05-2020
Publisher: IOP Publishing
Date: 03-02-2010
Publisher: Elsevier BV
Date: 12-2006
Publisher: Elsevier BV
Date: 10-2008
Publisher: Informa UK Limited
Date: 19-07-2017
Publisher: Elsevier BV
Date: 12-2013
Publisher: Elsevier BV
Date: 06-2013
Publisher: Elsevier BV
Date: 03-2006
Publisher: ASME International
Date: 02-02-2006
DOI: 10.1115/1.2190232
Abstract: An integral equation method is presented to determine dynamic elastic T-stress. Special attention is paid to a single crack in an infinite elastic plane subjected to impact loading. By using the Laplace and Fourier transforms, the associated initial-boundary value problem is transformed to a Fredholm integral equation. The dynamic T-stress in the Laplace transform domain can be expressed in terms of its solution. Moreover, an explicit expression for initial T-stress is derived in closed form. Numerically solving the resulting equation and performing the inverse Laplace transform, the transient response of T-stress is determined in the time space, and the response history of the T-stress is shown graphically. Results indicate that T-stress exhibits apparent transient characteristic.
Publisher: American Scientific Publishers
Date: 2013
Abstract: This paper studies the influence of surface elasticity on crack growth for a nanoscale crack advance. A crack is modeled as a double cantilever beam with consideration of surface stress. Using the Euler-Bernoulli beam theory incorporating with surface effects, a governing equation of static bending is derived and bending solution of a cantilever nanowire is obtained for a concentrated force at the free end. Based on the viewpoint of energy balance, the elastic strain energy is given and energy release rate is determined. The influences of the Surface stress and the surface elasticity on crack growth are discussed. Obtained results indicate that consideration of the surface effects decreases stress intensity factors or energy release rates. The residual surface tension impedes propagation of a nanoscale crack and apparent fracture toughness of nanoscale materials is effectively enhanced.
Publisher: Springer Science and Business Media LLC
Date: 16-04-2021
Publisher: Elsevier BV
Date: 08-2016
Publisher: Elsevier BV
Date: 12-2016
Publisher: Elsevier BV
Date: 11-2001
Publisher: AIP Publishing
Date: 09-03-2009
DOI: 10.1063/1.3094130
Abstract: This letter presents a theoretical treatment of Timoshenko [S. Timoshenko, Philos. Mag. 41, 744 (1921)] beams, in which the influences of shear deformation, rotary inertia, and scale coefficient are taken into account. Based on the nonlocal elasticity theory, coupled equations for transverse deflection and rotation of cross section are derived. Free vibration of several typical beams is analyzed. Explicit expressions for modal shapes of vibration are presented. Natural frequencies are evaluated for free vibration of simply supported beams, cl ed beams, cantilever beams, and cl ed-hinged beams. The effects of the nonlocal parameter on natural frequencies and modal shapes are discussed in detail.
Publisher: Elsevier BV
Date: 09-2016
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 03-2009
Publisher: Springer Science and Business Media LLC
Date: 22-06-2022
Publisher: Informa UK Limited
Date: 15-04-2018
Publisher: Informa UK Limited
Date: 03-10-2018
Publisher: Elsevier BV
Date: 08-2013
Publisher: Springer Science and Business Media LLC
Date: 20-06-2018
Publisher: Informa UK Limited
Date: 02-01-2019
Publisher: Elsevier BV
Date: 02-2018
Publisher: American Institute of Aeronautics and Astronautics (AIAA)
Date: 10-2019
DOI: 10.2514/1.T5667
Publisher: Elsevier BV
Date: 10-2019
Publisher: IOP Publishing
Date: 20-02-2002
Publisher: Wiley
Date: 20-07-2011
Publisher: Informa UK Limited
Date: 05-2013
Publisher: Springer Science and Business Media LLC
Date: 05-2012
Publisher: IOP Publishing
Date: 14-07-2005
Publisher: Elsevier BV
Date: 03-2013
Publisher: SAGE Publications
Date: 03-2013
DOI: 10.1260/1369-4332.16.3.549
Abstract: A tall building may be modeled as a shear beam since its bending is mainly induced by relative sliding of parallel floor slabs. Classical shear beams do not consider the presence of bending moment. Since the bending moment of a building can be originated from tension-compression force couple due to combined effects of strong wall-to-wall and wall-to-slab interactions, a modified shear beam theory cooperating with bending moment is needed. This paper gives a theoretical analysis of a refined shear beam model. Emphasis is placed on the determination of the natural frequencies of a shear beam on an elastic base such as soil and carrying a lumped mass. The characteristic equation for free vibration of a modified shear beam is obtained. The influences of translational and rotational spring stiffnesses, axially compressive loads and attached mass on the natural frequencies are illuminated.
Publisher: American Society of Civil Engineers (ASCE)
Date: 2022
Publisher: Informa UK Limited
Date: 21-06-2004
Publisher: World Scientific Pub Co Pte Lt
Date: 07-2012
DOI: 10.1142/S0219455412500277
Abstract: This paper studies buckling instability of columns with variable bending stiffness subjected to an axially compressive load. An analytic approach has been presented to determine critical buckling loads of a nonuniform column with or without continuous elastic restraint along its length. We transform this problem into a Fredholm equation, and then to a system of linear equations. The desired buckling loads can be easily obtained by solving the least positive eigenvalue of the resulting system. The validity and efficiency of the method is confirmed by comparing our numerical results with those available. The influences of variable cross-section or elastic restraint stiffness on the buckling loads of a simply-supported column are analyzed. A suboptimal design of a tapered cylindrical bar with fixed weight is given. The present results are of benefit to the optimal design of beam/column structures.
Publisher: Elsevier BV
Date: 09-2013
Publisher: Springer Science and Business Media LLC
Date: 10-2006
Publisher: No publisher found
Date: 2005
Publisher: Elsevier BV
Date: 10-2016
Publisher: Trans Tech Publications, Ltd.
Date: 2012
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.446-449.578
Abstract: The stability of Timoshenko columns with elastically supported ends under axially compressive force is analyzed. Characteristic equations are obtained according to an intermediate state between Haringx’s and Engesser’s models. For cl ed-free, cl ed-cl ed, and pinned-pinned columns, buckling loads are given in closed form. The influences of elastic restraint stiffness on the critical loads are elucidated. Haringx’s and Engesser’s models are two extreme cases of the present. Critical buckling loads using Haringx’s model are upper bound, and those using Engesser’s model are lower bound.
Publisher: Elsevier BV
Date: 09-2011
Publisher: Elsevier BV
Date: 07-2005
Publisher: Elsevier BV
Date: 11-2007
Publisher: AIP Publishing
Date: 04-2008
DOI: 10.1063/1.2903444
Abstract: The flexural wave behavior in carbon nanotubes embedded in an elastic medium is analyzed based on the classical and nonlocal theories of the Timoshenko beam. Emphasis is focused on the effects of small scale and the surrounding elastic medium on the phase velocity of the transverse wave. The system of basic equations for transverse deflection and rotation are derived, and further, a single fourth-order governing differential equation is reduced. The characteristic equation and dispersion relation are obtained for single-walled carbon nanotubes (SWCNTs) and double-walled carbon nanotubes (DWCNTs). The number of flexural wave branches depends only on the number of walls, but not on the surrounding elastic medium and the small scale parameter. A SWCNT has two phase velocities and a DWCNT has four phase velocities for extremely high frequencies. Critical or cutoff frequencies are independent of the small scale parameter. However, the lower critical frequencies depend on the surrounding elastic medium and the van der Waals force, and higher critical frequencies depend on the shear rigidity of tubes. Consideration of small scale decreases the corresponding wave speeds, and this effect is negligible for lower frequencies. A surrounding elastic medium affects the acoustic mode of phase velocity for lower frequencies, and hardly affects the optical mode. The classical/nonlocal Euler–Bernoulli and Rayleigh beam theories can be recovered as special cases of the present models. Moreover, the number of wave speeds for both SWCNTs and DWCNTs diminishes by half compared to that of the Timoshenko beam theory.
Publisher: Informa UK Limited
Date: 06-06-2022
Publisher: Elsevier BV
Date: 12-2016
Publisher: World Scientific Pub Co Pte Lt
Date: 20-12-2019
DOI: 10.1142/S0217984920500608
Abstract: Symmetric and anti-symmetric trapped modes in a cylindrical tube with a segment of higher density are studied. The problem is reduced to an eigenvalue problem of the spatial Helmholtz equation subject to vanishing Dirichlet boundary condition in the cylindrical coordinate system. Through the domain decomposition method and matching technique, multiple frequency parameters are determined by solving the characteristic equation, and the corresponding n-fold periodic trapped modes can be constructed. It is found that in addition to the fundamental mode, the second- and higher-order trapped modes exist, which depend on the density ratio and length of the inhomogeneity. The local inhomogeneity leads to a decrease of the cutoff frequencies of the homogeneous tube and the corresponding vibration mode is localized near the inhomogeneous segment.
Publisher: Wiley
Date: 18-05-2009
Publisher: Elsevier BV
Date: 07-2007
Publisher: Elsevier BV
Date: 2015
DOI: 10.1016/J.ULTRAS.2014.08.002
Abstract: Free vibration and mass detection of carbon nanotube-based sensors are studied in this paper. Since the mechanical properties of carbon nanotubes possess a size effect, the nonlocal beam model is used to characterize flexural vibration of nanosensors carrying a concentrated nanoparticle, where the size effect is reflected by a nonlocal parameter. For nanocantilever or bridged sensor, frequency equations are derived when a nanoparticle is carried at the free end or the middle, respectively. Exact resonance frequencies are numerically determined for cl ed-free, simply-supported, and cl ed-cl ed resonators. Alternative approximations of fundamental frequency are given in closed form within the relative error less than 0.4%, 0.6%, and 1.4% for cantilever, simply-supported, and bridged sensors, respectively. Mass identification formulae are derived in terms of the frequency shift. Identified masses via the present approach coincide with those using the molecular mechanics approach and reach as low as 10(-24)kg. The obtained results indicate that the nonlocal effect decreases the resonance frequency except for the fundamental frequency of nanocantilever sensor. These results are helpful to the design of micro/nanomechanical zeptogram-scale biosensor.
Publisher: Elsevier BV
Date: 06-2005
Publisher: American Society of Civil Engineers (ASCE)
Date: 04-2013
Publisher: Springer Science and Business Media LLC
Date: 27-10-2005
Publisher: Springer Science and Business Media LLC
Date: 23-09-2009
Publisher: Elsevier BV
Date: 07-2019
Publisher: Elsevier BV
Date: 08-2002
Publisher: Elsevier BV
Date: 05-2010
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 07-2010
Publisher: Elsevier BV
Date: 09-2015
Publisher: Elsevier BV
Date: 02-2013
Publisher: Elsevier BV
Date: 04-2019
Publisher: Springer Science and Business Media LLC
Date: 30-04-2022
Publisher: Elsevier BV
Date: 2005
Publisher: Elsevier BV
Date: 12-2018
Publisher: Elsevier BV
Date: 05-2007
Publisher: Springer Science and Business Media LLC
Date: 08-05-2010
Publisher: Elsevier BV
Date: 04-2008
Publisher: Elsevier BV
Date: 12-2014
Publisher: Springer Science and Business Media LLC
Date: 19-01-2010
Publisher: Elsevier BV
Date: 12-2008
Publisher: Elsevier BV
Date: 02-2012
Publisher: Springer Science and Business Media LLC
Date: 13-02-2013
Publisher: Elsevier BV
Date: 08-2010
DOI: 10.1016/J.ULTRAS.2010.03.001
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.
Publisher: Elsevier BV
Date: 02-2013
Publisher: Springer Science and Business Media LLC
Date: 26-04-2016
Publisher: Informa UK Limited
Date: 05-09-2019
Publisher: Elsevier BV
Date: 06-2007
Publisher: Elsevier BV
Date: 08-2017
Publisher: IOP Publishing
Date: 22-02-2008
Publisher: Elsevier BV
Date: 2013
Publisher: Informa UK Limited
Date: 15-04-2010
Publisher: Springer Science and Business Media LLC
Date: 16-05-2022
Publisher: Elsevier BV
Date: 04-2006
Publisher: Elsevier BV
Date: 05-2021
Publisher: Wiley
Date: 10-2001
DOI: 10.1002/1521-3951(200110)227:2<613::AID-PSSB613>3.0.CO;2-W
Publisher: Elsevier BV
Date: 07-2003
Publisher: Elsevier BV
Date: 03-2002
Publisher: Wissenschaftliche Verlagsgesellschaft mbH
Date: 2018
DOI: 10.3813/AAA.919148
Publisher: Elsevier BV
Date: 02-2017
Publisher: ASME International
Date: 08-2011
DOI: 10.1115/1.4005489
Abstract: The potential of double-walled carbon nanotubes (DWCNTs) as a micromass sensor is explored. A nonlocal Timoshenko beam carrying a micromass at the free end of the inner tube is used to analyze the vibration of DWCNT-based mass sensor. The length of the outer tube is not equal to that of the inner tube, and the interaction between two tubes is governed by van der Waals force (vdW). Using the transfer function method, the natural frequencies of a nonlocal cantilever with a tip mass are computed. The effects of the attached mass and the outer-to-inner tube length ratio on the natural frequencies are discussed. When the nonlocal parameter is neglected, the frequencies reduce to the classical results, in agreement with those using the finite element method. The obtained results show that increasing the attached micromass decreases the natural frequency but increases frequency shift. The mass sensitivity improves for short DWCNTs used in mass sensor. The nonlocal Timoshenko beam model is more adequate than the nonlocal Euler-Bernoulli beam model for short DWCNT sensors. Obtained results are helpful to the design of DWCNT-based resonator as micromass sensor.
Publisher: Informa UK Limited
Date: 06-03-2023
Publisher: Informa UK Limited
Date: 11-02-2009
Publisher: Springer Science and Business Media LLC
Date: 03-08-2021
Publisher: Elsevier BV
Date: 07-2012
Publisher: Wiley
Date: 18-11-2013
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 02-2012
Publisher: AIP Publishing
Date: 04-2009
DOI: 10.1063/1.3103322
Abstract: This paper studies the size effect in the transverse deformation of nanowires or nanoropes subjected to flexural bending. Based on the classic strain-gradient theory, a continuum approach is proposed, in which the strain energy was expressed in terms of the linear strains and strain gradients, and two additional phenomenological internal parameters were introduced. The governing equation for the flexural deformation of the nanowires was derived according to the principle of minimum potential energy. In particular, the deformations of the nanowires under two support conditions were determined explicitly, i.e., a cantilever nanowire and a fixed nanowire. Numerical ex les were demonstrated to indicate the dependence of the effective modulus and bending stiffness upon the nanowire diameter and aspect ratio. The predictions given by the present model are consistent very well with the experimental measurements reported in the recent literature. The proposed model can be further used to explain the size effect in other properties of nanowires such as dynamics and thermal properties, among others.
Publisher: Elsevier BV
Date: 06-2004
Publisher: SAGE Publications
Date: 08-10-2015
Abstract: This paper presents a theoretical analysis of free vibration and forced vibration of nanowires with surface effects. Using the Timoshenko beam theory incorporated with the surface effects, exact frequency equations are derived for various end supports. Natural frequencies and mode shapes are determined for simply supported, cl ed-cl ed, and cl ed-free ends. Forced vibration of nanowires is also treated by superposing vibration modes of free vibration. An inverse problem is further investigated to determine the size-dependent effective Young's modulus of nanowires. Obtained results for a nanowire with residual stress and surface elasticity are confirmed by comparing them with the results using the finite element method. Theoretical natural frequencies and finite element method simulation have good agreement with the results from experimental data and molecular dynamics simulation. The effect of surface stress on forced vibration is analyzed. Residual surface tension has a more significant influence on the frequencies and a somewhat effect on the mode shapes.
Publisher: Springer Science and Business Media LLC
Date: 21-11-2018
Publisher: Informa UK Limited
Date: 29-01-2010
Publisher: Springer Science and Business Media LLC
Date: 10-07-2011
Publisher: Springer Science and Business Media LLC
Date: 30-12-2016
Publisher: Elsevier BV
Date: 04-2005
Publisher: Wiley
Date: 10-06-2020
Publisher: Elsevier BV
Date: 07-2004
Publisher: ASME International
Date: 08-10-2018
DOI: 10.1115/1.4041419
Abstract: In this paper, a non-Fourier model of heat conduction and moisture diffusion coupling is proposed. We study a hygrothermal elastic problem within the framework of time-fractional calculus theory for a centrally symmetric sphere subjected to physical heat and moisture flux at its surface. Analytic expressions for transient response of temperature change, moisture distribution, displacement, and stress components in the sphere are obtained for heat/moisture flux pulse and constant heat/moisture flux at the sphere's surface, respectively, by using the integral transform method. Numerical results are calculated and the effects of fractional order on temperature field, moisture distribution, and hygrothermal stress components are illustrated graphically. Subdiffusive and super-diffusive transport coupling behavior as well as wave-like behavior are shown. When fractional-order derivative reduces to first-order derivative, the usual heat and moisture coupling is recovered, which obeys Fourier heat conduction and Fick's moisture diffusion.
Publisher: IOP Publishing
Date: 14-09-2018
Publisher: Springer Science and Business Media LLC
Date: 17-07-2020
Publisher: Elsevier BV
Date: 07-2007
Publisher: Elsevier BV
Date: 09-2004
Publisher: Elsevier BV
Date: 06-2019
Publisher: Elsevier BV
Date: 12-2007
Publisher: Springer Science and Business Media LLC
Date: 13-12-2008
Publisher: Springer Science and Business Media LLC
Date: 02-07-2020
Publisher: Elsevier BV
Date: 05-2015
Publisher: World Scientific Pub Co Pte Lt
Date: 06-2016
DOI: 10.1142/S0219455415500170
Abstract: The stability of a nonuniform column subjected to a tip force and axially distributed loading is investigated based on the Timoshenko beam theory. An emphasis is placed on buckling of a standing column with varying cross-section and variable material properties under self-weight and tip force. Four kinds of columns with different taper ratios are analyzed. A new initial value method is suggested to determine critical tip force and axial loading at buckling. The effectiveness of the method is confirmed by comparing our results with those for Euler–Bernoulli columns for the case of sufficiently large shear rigidity. The effects of shear rigidity, taper ratio, and gravity loading on the buckling loads of a heavy standing or hanging column are examined.
Publisher: Elsevier BV
Date: 07-2009
Publisher: Elsevier BV
Date: 11-2022
Publisher: Elsevier BV
Date: 12-2022
Publisher: Elsevier BV
Date: 2002
Publisher: IOP Publishing
Date: 11-03-2004
Publisher: Elsevier BV
Date: 2019
Publisher: Wiley
Date: 23-11-2018
Publisher: SAGE Publications
Date: 02-07-2009
Abstract: The analysis of the large deformation of a non-linear cantilever functionally graded material (FGM) beam is made. When subjected to an end moment, explicit expressions for deflection and rotation are derived for a functionally graded beam with work hardening of power law. The effects of the gradient distribution of Young’s modulus and the material non-linearity parameter on the deflections of the FGM beam are analyzed. Our results show that depth-dependent Young’s modulus and material non-linearity have a significant influence on the deflections of the beam, and a FGM beam can bear larger applied load than a homogeneous beam. Moreover, to determine an optimal gradient distribution, an optimum design of a beam of a lighter weight and larger stiffness is given. The influence of the geometric non-linearity of the beam is also studied. Large and small deformation theories predict nearly the same deflections with 5% error when rotation is less than 45°, and the predictions based on the small deformation theory are overestimated to exceed 10% when rotation is greater than 60°.
Publisher: Elsevier BV
Date: 04-2006
Publisher: Elsevier BV
Date: 06-2008
Publisher: ASME International
Date: 20-01-2006
DOI: 10.1115/1.2188016
Abstract: This paper is concerned with the T-stress change before and after crack kinking in two-dimensional elastic solids. By using asymptotic analysis and the Westergaard stress function method, approximate analytical formulas for calculating the T-stress as well as stress intensify factors of an infinitesimal kink are given. Contributions from the T-stress before crack kinking, to the T-stress and the stress intensity factors of the kinked crack, are clearly described. It is noted that since the sign of the T-stress of a kinked open crack might be different from that of a main crack, simply using the sign of the T-stress before crack kinking is not sufficient to determine crack growth stability as observed in recent experiments.
Publisher: American Society of Civil Engineers (ASCE)
Date: 2018
Publisher: Elsevier BV
Date: 09-2010
Publisher: Elsevier BV
Date: 09-2022
Publisher: Springer Science and Business Media LLC
Date: 08-2019
Publisher: Elsevier BV
Date: 09-2015
Publisher: Elsevier BV
Date: 08-2011
Publisher: Elsevier BV
Date: 07-2004
Publisher: Springer Science and Business Media LLC
Date: 03-10-2018
Publisher: Springer Science and Business Media LLC
Date: 14-09-2017
Publisher: Springer Science and Business Media LLC
Date: 16-10-2017
Publisher: Wiley
Date: 20-01-2015
Publisher: Elsevier BV
Date: 2005
Publisher: Elsevier BV
Date: 08-2016
Publisher: Acoustical Society of America (ASA)
Date: 03-2020
DOI: 10.1121/10.0000855
Abstract: A third-order shear deformation beam model is proposed to analyze dynamic behavior of straight hollow cylinders of annular cross-section, in which shear stress vanishes on the inner and outer surfaces of the pipe. Shear deformation, warping, and rotational inertia of cross-section are all considered, and the shear correction factor is not needed. A single governing differential equation is derived for analyzing flexural wave propagation and free vibration of straight pipe-beams. The phase and group speeds of flexural waves propagating in pipes are determined for acoustic and optical modes. The dispersion of flexural waves is analyzed. The frequency equations are obtained explicitly for pipe-beams with ten typical boundary conditions including cl ed, pinned, guided, and free ends. The natural frequencies of cl ed-free, cl ed-cl ed, and pinned-pinned pipe-beams are evaluated for the first four vibration modes. A comparison of this paper's numerical results of the natural frequencies with the previous ones is made and turns out the effectiveness of the suggested method. The influences of the pipe's thickness and length on the natural frequencies and mode shapes for a cantilever pipe are presented.
Publisher: IEEE
Date: 12-2009
Publisher: Elsevier BV
Date: 02-2018
Publisher: Elsevier BV
Date: 12-2008
Publisher: Springer Science and Business Media LLC
Date: 19-01-2018
Publisher: ASME International
Date: 26-09-2005
DOI: 10.1115/1.2130734
Abstract: The transient response of a finite bimaterial plate with a crack perpendicular to and terminating at the interface is analyzed for two types of boundaries (free-free and cl ed-cl ed). The crack surface is loaded by arbitrary time-dependent antiplane shear impact. The mixed initial-boundary value problem is reduced to a singular integral equation of a generalized Cauchy kernel for the crack tearing displacement density or screw dislocation density. The Gauss-Jacobi quadrature technique is employed to numerically solve the singular integral equation, and then the dynamic stress intensity factors are determined by implementing a numerical inversion of the Laplace transform. As an ex le, numerical calculations are carried out for a cracked bimaterial plate composed of aluminum (material I) and epoxy or steel (material II). The effects of material properties, geometry, and boundary types on the variations of dynamic stress intensity factors are discussed in detail. Results indicate that an overshoot of the normalized stress intensity factor of the crack tip at the interface decreases for a cracked bimaterial plate, and the occurrence of which is delayed for a cracked aluminum/epoxy plate compared to a pure aluminum plate with the same crack.
Publisher: IOP Publishing
Date: 23-12-2019
Publisher: Elsevier BV
Date: 07-2005
Publisher: Elsevier BV
Date: 08-2017
Publisher: Elsevier BV
Date: 11-2006
Publisher: Elsevier BV
Date: 06-2012
Publisher: Elsevier BV
Date: 07-2015
Publisher: ASME International
Date: 11-2004
DOI: 10.1115/1.1795219
Abstract: Previous studies assumed that a crack is either impermeable or permeable, which are actually two limiting cases of a dielectric crack. This paper considers the electroelastic problem of a three-dimensional transversely isotropic piezoelectric material with a penny-shaped dielectric crack perpendicular to the poling axis. Using electric boundary conditions controlled by the boundaries of an opening crack, the electric displacements at the crack surfaces are determined. The Hankel transform technique is employed to reduce the considered problem to dual integral equations. By solving resulting equations, the results are presented for the case of remote uniform loading, and explicit expressions for the electroelastic field at any point in the entire piezoelectric body are given in terms of elementary functions. Moreover, the distribution of asymptotic field around the crack front and field intensity factors are determined. Numerical results for a cracked PZT-5H ceramic are evaluated to examine the influence of the dielectric permittivity of the crack interior on the field intensity factors, indicating that the electric boundary conditions at the crack surfaces play an important role in determining electroelastic field induced by a crack, and that the results are overestimated for an impermeable crack, and underestimated for a permeable crack.
Publisher: Springer Science and Business Media LLC
Date: 12-02-2015
Publisher: Mathematical Sciences Publishers
Date: 07-04-2019
Publisher: Elsevier BV
Date: 06-2003
Publisher: Elsevier BV
Date: 09-2023
Publisher: Elsevier BV
Date: 07-2010
Publisher: Elsevier BV
Date: 04-2017
Publisher: Elsevier BV
Date: 03-2012
Publisher: Springer Science and Business Media LLC
Date: 09-07-2022
Publisher: American Scientific Publishers
Date: 08-2009
Publisher: Elsevier BV
Date: 10-2011
Publisher: Elsevier BV
Date: 09-2010
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 04-2014
Publisher: Elsevier BV
Date: 11-2002
No related grants have been discovered for Xian-Fang Li.