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1.
Propagation of two-dimensional nonstationary vibrations in an electrically excited piezoceramic prismatic body 总被引:1,自引:1,他引:0
The paper outlines a numerical method to solve a plane problem for a piezoceramic prismatic body having rectangular cross-section
and undergoing mechanically excited nonstationary vibrations. The features of the onset and propagation of vibrations are
studied. The dynamic state of bodies with different widths is analyzed. The thickness and transverse displacements versus
time are plotted
Translated from Prikladnaya Mekhanika, Vol. 44, No. 11, pp. 71–78, November 2008. 相似文献
2.
V. L. Karlash 《International Applied Mechanics》2005,41(7):709-747
The scientific results on the resonant electromechanical vibrations of piezoceramic plates in the form of disks, rings, and
polygons obtained over the last 30 years are analyzed, systematized, and generalized. Emphasis is on experimental methods.
It is shown that all piezoceramic plates have vibration modes at which deformations are in-phase over the entire volume of
the body
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Translated from Prikladnaya Mekhanika, Vol. 41, No. 7, pp. 3–46, July 2005. 相似文献
3.
Radial vibrations and dissipative heating of a polarized piezoceramic ring plate are studied. The plate is excited by a harmonic electric field applied to nonuniformly electroded surfaces of the plate. The viscoelastic behavior of piezoceramics is described in terms of complex quantities. An analytical solution is found in the case of quasistatic harmonic loading. The dynamic nonlinear problem of coupled thermoviscoelasticity is solved with regard for the temperature dependence of the properties of piezoceramics by step-by-step integration in time, using the numerical methods of discrete orthogonalization and finite differences. A numerical analysis is conducted for TsTStBS-2 piezoceramics to study the influence of partial electroding on the stress–strain distribution, natural frequency, and amplitude–frequency and temperature–frequency characteristics 相似文献
4.
An in-depth stress analysis of a piezoceramic plate is carried out using complex-variable theory and an experimental method. The first eight modes in the spectrum of planar vibrations of the rectangular piezoceramic transformer are identified. It is particularly established that the transformation ratios in the first and second and in the third and sixth longitudinal modes are practically equal 相似文献
5.
The problem of the free axisymmetric vibrations of longitudinally polarized piezoceramic hollow cylinders is solved by a numerical
analytic method. The spline-collocation method with respect to the longitudinal coordinate is used to reduce the original
problem of electroelasticity to an eigenvalue boundary-value problem for ordinary differential equations with respect to the
radial coordinate. This problem is solved by the stable discrete-orthogonalization and incremental search methods. Numerical
results are presented and the natural frequencies of the cylinders are analyzed for a wide range of their geometric characteristics 相似文献
6.
The coupled problem of the forced axisymmetric vibrations and self-heating of electrothermoviscoelastic cylindrical shells
with piezoceramic actuators under monoharmonic electromechanical loading is solved. The temperature dependence of the complex
characteristics of the passive and piezoactive materials is taken into account. The coupled nonlinear problem of electrothermoelasticity
is solved by using a time-marching method with discrete orthogonalization at each time step (to integrate the equations of
elasticity) and an explicit finite-difference method (to solve the heat-conduction equations). An analysis is made of the
effect of the boundary conditions at the shell ends, the dimensions of the piezoactuator, and the self-heating temperature
on the actuator voltage and the effectiveness of active damping of the forced vibrations of the shell under uniform transverse
monoharmonic pressure 相似文献
7.
I. F. Kirichok 《International Applied Mechanics》2005,41(9):1037-1042
The flexural vibrations and dissipative heating of a circular bimorph piezoceramic plate are studied. The plate is excited
by a harmonic electric field applied to nonuniformly electroded surfaces. The viscoelastic behavior of piezoceramics is described
in terms of temperature-dependent complex moduli. The nonlinear coupled problem of thermoviscoelasticity is solved by step-by-step
integration in time, using the discrete-orthogonalization method to solve the mechanics equations and the finite-differences
method to solve the heat-conduction equations. A numerical analysis is conducted for TsTStBS-2 piezoceramics to study the
influence of the nonuniform electroding on the resonant frequency, amplitude, and modes of flexural vibrations and the amplitude-
and temperature-frequency characteristics of the plate
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Translated from Prikladnaya Mekhanika, Vol. 41, No. 9, pp. 94–100, September 2005. 相似文献
8.
The monoharmonic radial vibrations and dissipative heating of an infinite hollow piezoceramic cylinder are studied in dynamic formulation, taking into account the temperature dependence of the complex electromechanical characteristics over a wide range of temperatures, including depolarization temperatures. The influence of the heat exchange conditions, the level of electric load, and geometry on the thermoelectromechanical characteristics is studied in the case of forced vibrations at the first resonance__________Translated from Prikladnaya Mekhanika, Vol. 41, No. 3, pp. 101–107, March 2005. 相似文献
9.
I. F. Kirichok 《International Applied Mechanics》2011,46(8):890-901
The coupled problem of forced vibrations and self-heating of thermoviscoelectroelastic shells of revolution with piezoceramic
sensor and actuator under monoharmonic loading is solved. The temperature dependence of the complex characteristics of the
passive and piezoactive materials is taken into account. The coupled nonlinear problem of thermoelectroelasticity is solved
by time-marching integration, using discrete orhogonalization to integrate the equations of elasticity and explicit finite
differencing to solve the heat conduction equation. The effect of the dimensions of the sensor and actuator and self-heating
on the sensor voltage and on the active damping of forced vibrations of a circular plate under uniform monoharmonic transverse
pressure is studied 相似文献
10.
V. L. Karlash 《International Applied Mechanics》2009,45(10):1120-1126
Results on the resonant electromagnetic vibrations of piezoceramic half-disks are analyzed, systematized, and generalized.
Considerable attention is paid to new experimental methods for and results of studying resonant vibrations 相似文献
11.
V. L. Karlash 《International Applied Mechanics》2007,43(5):547-553
An attempt is made to systematize experimental data for a rectangular piezoceramic plate and to compare them with those on
planar vibrations of a thin piezoceramic half-disk. Experimental data on planar vibrations of a half-disk are discussed for
the first time. Neighboring vibration modes of a rectangular plate with solid electrodes demonstrate strong superposition
and coupling
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Translated from Prikladnaya Mekhanika, Vol. 43, No. 5, pp. 89–96, May 2007. 相似文献
12.
Non-linear cylindrical-form vibrations of an electroconductive plate-strip in longitudinal and transverse magnetic fields are considered. For the plate material a non-linear relationship between stress and deformation is accepted. On the basis of the known hypotheses and assumptions the general system is reduced to one equation for the normal displacement of the plate. Using the Bubnov-Galerkin method and the method of asymptotic integration, the amplitude-frequency characteristics of vibrations are defined. On the basis of numerical analysis different degrees of the influence of various factors (non-linearity, magnetic field, conductivity, etc.) on the nature of vibrations are compared. Qualitative and quantitative differences between the nature of vibrations in longitudinal and transverse magnetic fields are revealed. 相似文献
13.
Free nonaxisymmetric vibrations of radially polarized hollow piezoceramic cylinders of finite length
The three-dimensional problem of free nonaxisymmetric vibrations of hollow piezoceramic cylinders with axial polarization
is considered. An efficient numerical analytic method to solve boundary-value problems is proposed. The original three-dimensional
problem of electroelasticity is reduced to a two-dimensional problem by representing the displacement components as standing
circumferential waves. Spline collocation with respect to the axial coordinate is used to reduce this two-dimensional problem
to an eigenvalue boundary-value problem with respect to the radial coordinate. This problem is solved by the stable discrete-orthogonalization
and incremental-search methods. Numerical results are presented and the natural frequencies of the cylinders are analyzed
in a wide range of their geometric characteristics 相似文献
14.
袋型阻尼密封泄漏流动和转子动力特性的研究进展 总被引:4,自引:0,他引:4
袋型阻尼密封可以有效地减弱密封间隙内泄漏流体的周向流动, 从而使转子具有优良的动力特性. 本文简介了袋型阻尼密封的发展历程, 详细综述了袋型阻尼密封的泄漏和转子动力特性的理论分析、实验测量和数值预测的研究进展. 介绍了袋型阻尼密封转子动力特性的系统阻抗法和腔室动态压力响应法两种实验测试技术及其应用. 最后在袋型阻尼密封研究综述的基础上, 展望了袋型阻尼密封的研究重点和发展方向. 相似文献
15.
The transverse vibrations of a circular disk of uniform thickness rotatingabout its axis with constant angular velocity are analyzed. The resultsspecialized to the linear case of disks clamped at the center and free atthe periphery are in good agreement with those reported in the literature.The natural frequencies of spinning hard and floppy disks are obtained for various nodal diameters and nodal circles. Primary resonance is shown to occur at the critical rotational speed at which, in the linear analysis, the spinning disk is unable to support arbitraryspatially fixed transverse loads. Using the method of multiple scales, wedetermine a set of four nonlinear ordinary-differential equations governingthe modulation of the amplitudes and phases of two interacting modes. Thesymmetry of the system and the loading conditions are reflected in thesymmetry of the modulation equations. They are reduced to an equivalentset of two first-order equations whose equilibrium solutions aredetermined analytically. The stability characteristics of thesesolutions is studied; the qualitative behavior of the response isindependent of the mode being considered. 相似文献
16.
A Nonlinear Vibration Absorber for Flexible Structures 总被引:6,自引:0,他引:6
An approach for implementing an active nonlinear vibration absorber for flexible structures is presented. The technique exploits the saturation phenomenon exhibited by multidegree-of-freedom systems with quadratic nonlinearities possessing two-to-one autoparametric resonances. The strategy consists of introducing second-order controllers and coupling each of them with the plant through a sensor and an actuator, where both the feedback and control signals are quadratic. Once the structure is forced near its resonances, the oscillatory response is suppressed through the saturation phenomenon. We present theoretical and experimental results of the application of the proposed vibration absorber. The structure consists of a cantilever beam, the feedback signal is generated by a strain gage, and the actuation is achieved through piezoceramic patches. The equations of motion are developed and analyzed through perturbation techniques and numerical simulation. Then, the strategy is tested by assembling the controllers in electronic components and suppressing the vibrations of the first and second modes of two beams. 相似文献
17.
Jörg Wauer 《Flow, Turbulence and Combustion》1998,61(1-4):161-177
As a generalization considering small fluid-structural vibrations, the present paper examines the finite magnitude oscillatory
motion of an elastically supported rigid cylinder in a cylindrical rigid duct conveying a compressible flow. The fluid is
assumed to be inviscid and irrotational and free purely transverse vibrations of the body are dealt with. The governing equations
of motion are the fully nonlinear Euler equations together with the continuity equation and a state equation (here for an
ideal gas), the ordinary differential equation for the vibrating cylinder, and the kinematical transition and boundary conditions
at the moving contact interface between fluid and body and the outside fluid border, respectively. A pertubation analysis
is performed to calculate not only the dynamic characteristics for small coupled oscillations but also the corrections due
to the inherent nonlinearities of the vibroacoustic problem. To make the calculation steps more transparent, the simpler problem
of a two-dimensional channel flow between a rigid wall and an elastically supported rigid plate is also included in the present
study. As an outlook, the influence of flexibility of the cylinder (or the plate) is addressed and the problem of forced vibrations
is touched.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
18.
International Applied Mechanics - Experimental results on the forced radial and thickness vibrations of circular piezoceramic plates are analyzed. Experimental and theoretical... 相似文献
19.
Piezoceramic transducers, acting as actuators and sensors, are attractive for generation and reception of Lamb waves in Structural
Health Monitoring (SHM) systems. To get insight into the source-mechanisms of Lamb waves, the vibrations of piezoceramic actuators
are analyzed for the free and bonded state of the piezoceramic by analytical and finite element (FEM) calculations. Mode shapes
and spectra of piezoceramic actuators and Lamb wave fields are experimentally recorded by scanning laser vibrometry. The analytical
solutions for bending modes are shown to be valid for large diameter-to-thickness-relations of a free piezoactuator (D/H > 10)
only. For thicker piezoceramics, a FEM-solution gives better results. Calculated frequencies for radial modes of vibration
are confirmed by 3-D-laser-vibrometry and measurements of electrical impedance. The bonded case of a piezoactuator exhibits
a broad resonance peak resulting from the strong coupling between radial and bending modes. The assumption that optimal excitation
of Lamb modes occurs for a matching of the wavelengths to the diameter of the piezoceramic holds only for thin ceramics. Otherwise
the distinct modes of out-of-plane and in-plane vibrations control the excitation of the Lamb modes more than the wavelength
matching. 相似文献
20.
V. L. Karlash 《International Applied Mechanics》2008,44(4):361-387
Scientific results from studies on the resonant electromechanical vibrations of piezoceramic thin-walled shells of revolution,
their fragments, and segmented cylinders are analyzed, systematized, and generalized. Considerable attention is focused on
experimental studies of resonant vibrations. It is shown that the modes in which deformation occurs inphase throughout the
volume are of the highest intensity in all piezoceramic shell structures
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Translated from Prikladnaya Mekhanika, Vol. 44, No. 4, pp. 3–34, April 2008. 相似文献