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The paper is devoted to investigation of mechanical response of an electro-viscoelastic structure (a structure with piezoelectric element attached to its surface) in case when electric voltage with prescribed parameters is applied to electrodes of piezoelectric element. A cantilever plate was considered as such a structure. An amplitude of displacements of the free end of the plate at resonant modes is considered as a mechanical response in case when forced steady-state vibrations occurring under kinematic or force loading are considered. Mechanical response of the structure is determined numerically using the ANSYS software package. Viscoelastic properties of a material of the plate are taken into account using the model with complex dynamic moduli. Within the frameworks of this paper relations between mechanical response of the structure and magnitude and polarity of electric voltage applied to electrodes of a piezoelectric element was obtained with respect to a type of excitation of vibrations. [ABSTRACT FROM AUTHOR]

The paper demonstrates the possibility of controlling the dissipative properties of structures containing viscoelastic elements by adding piezoelectric elements, to the electrodes of which external electrical circuits are connected. On the basis of the results of solution to the problem of natural vibrations of piecewise-homogeneous electro-viscoelastic bodies with passive external electric circuits, an analysis of the effect of a shunted piezoelectric element on the damping coefficients of an electro-viscoelastic system was carried out. A two-layer shell structure is adopted as the object of research. The outer layer of the shell is made of elastic, and the inner one is made of viscoelastic materials. For the case of attaching resistive-shunted piezoelectric element it was shown that a resulting damping coefficient for the specified vibration mode is not a simple algebraic sum of damping coefficient obtained for a viscoelastic structure without piezoelectric element and the one obtained for an elastic structure with resistive-shunted piezoelectric element (in case when resistance of a shunting circuit is optimally chosen). At the same time, an attention is drawn to the fact that if the damping coefficient of the corresponding vibration mode decreases when only a piezoelectric element is connected, then even when a resistive circuit with optimal parameters is connected to it, the final damping coefficient for this vibration mode may be lower than that of a structure without a piezoelectric element. [ABSTRACT FROM AUTHOR]

The use of elements made of piezoelectric materials and connected to external passive electric RLC-circuits is one of the effective ways of damping the vibrations of structure elements. The key problem for this technique is identification of optimal parameters for the elements of the external circuits, which can provide maximal damping of a single mode or simultaneous damping of several modes. In this study, based on the mathematical formulation of the natural vibration problem for electroelastic bodies with external electric circuits we have developed an approach for evaluating the parameters of the external RL-circuit which can provide maximal damping of the particular vibration modes. A criterion for determining the external circuit parameters has been proposed based on the analysis of the obtained vibrational complex eigenfrequencies. For implementation of the proposed approach a finite-element algorithm has been constructed using the commercial ANSYS software package. A series of numerical experiments have been carried out for e few objects to test the performance of the developed technique. [ABSTRACT FROM AUTHOR]

The presence of the elements, which work as sensors or actuators, is one of the main features of smart-constructions. These elements are commonly made of piezoelectric materials, the main feature of which is a direct and inverse piezoelectric effect, which allows its functioning as a sensor and actuator. In addition, one and the same element can combine both functions. Moreover electroding of surfaces of the piezoelectric elements provides an additional means of controlling the dynamic processes due to application of different electric circuits connected to piezoelectric elements. The location of the piezoelectric element, its size and geometry play a significant role in damping the vibration of structures containing elements made of piezoelectric materials. In this paper, a comparative analysis of different possible options of smart-function realization is made by comparing the patterns of strains and electric potentials generated on the piezoelectric element surface. The numerical results of determining the optimal piezoelectric element location, which will provide the generation of maximal electric potential at certain resonant frequencies, are presented. The numerical implementation is carried out by the finite element method using the commercial ANSYS software package. [ABSTRACT FROM AUTHOR]