Piezoelectric–mechanical–acoustic couplings from a PZT-actuated vibrating beam and its sound radiation (original) (raw)
Related papers
Finite element modeling of sound fields from a beam with shunted piezoceramics
Sound radiation of cantilever beam with electrically shunted piezoceramic materials (PZT) employed to decreasing sound emission level is investigated. Two sets of collocated piezoelectric transducers were bonded to the beam. One of these pairs served to drive the beam, whilst the second pair is used to sensing (first transducer) and vibrations control (second transducer). Vibrations damping is performed by shunted passive resonant electrical circuits in series RL configuration. The piezoelectric materials convert mechanical energy to electrical energy, which can be dissipated via an electric impedance. An electric circuit is optimally tuned to the mechanical resonance frequency in a manner corresponding to a mechanical vibration absorber. Sound radiation from the vibrating beam is simulated in a half sphere of air surrounding the beam and is obtained for three resonance frequencies, with and without a controller.
Acta Physica Polonica A, 2010
The paper presents simulations and research results of testing of the aluminium plate with active vibration control. The aim of this paper is to analyze and compare two ways of excitation of the test plate, various influence on its vibrations and active damping control. Vibration control of the smart structure is realized through four piezoceramic PZT actuators and one PZT sensor bonded to the plate. Simulations and numerical computations of the structure are performed in ANSYS environment. Measurements are executed on specialized sound insulation suite for small elements in reverberation chamber. At the beginning white noise sound source is used in purpose to measure basic vibration modes. After numerical computations and measurements three particular frequencies has been chosen and for them active damping is applied. There are two ways of exciting the test plate; first method is sound wave, second is mechanical vibrations via one of piezoceramics. The test results indicate that PZTs can decrease vibrations by approximately 15 dB for a pure sound input with acoustic excitation method, for mechanical excitation method 18 dB for a sinus vibration signal is achieved.
Structural acoustic control of a one side loaded circular plate with piezoelectric actuators
2011
The experiment presented in this paper is a part of an ongoing research project connected with the structural acoustic control in one side fluid loading structures. The system considered in the study is built up of a thin, circular plate and eight square piezoelectric elements. The plate is clamped along its edge by finite rigid co-planer baffle. The baffle with other four rigid walls is formed aquarium filled with water. Numerical computations utilize the FEM approach supported by Ansys software. The natural frequencies were determined using modal analysis. The harmonic analysis covers the acoustic radiation due to steady-state plate vibrations for the first two modes of natural vibrations. Each mode was examined individually. The test results indicate that actuators as flexural wave-source can decrease the displacement response as well as sound radiation for a pure tone input.
Finite element modeling of piezoelectric structures
The design of control systems involving piezoelectric actuators and sensors requires an accurate knowledge of the transfer functions between the inputs and the outputs of the system. These are not easy to determine numerically, particularly for shell structures with embedded distributed actuators and sensors. The situation where they are nearly collocated is particularly critical, because the zeros of the transfer functions are dominated by local effects which can only be accounted for by finite elements. This paper presents a general finite element formulation for piezoelectrically coupled systems. Piezoelectric finite elements were developed based on Mindlin shell elements and integrated in the FE package Samcef. Volume elements have also been derived and integrated. Volume finite element and shell finite element solutions are compared for the bimorph device. A shear actuation device is modelized. The interfacing with a control oriented software environment is discussed and non-trivial applications in noise and vibration control are presented.
Journal of Sound and Vibration, 2012
A novel active control method of sound radiation from a cylindrical shell under axial excitations is proposed and theoretically analyzed. This control method is based on a pair of piezoelectric stack force actuators which are installed on the shell and parallel to the axial direction. The actuators are driven in phase and generate the same forces to control the vibration and the sound radiation of the cylindrical shell. The model considered is a fluid-loaded finite stiffened cylindrical shell with rigid end-caps and only low-frequency axial vibration modes are involved. Numerical simulations are performed to explore the required control forces and the optimal mounting positions of actuators under different cost functions. The results show that the proposed force actuators can reduce the radiated sound pressure of low-frequency axial modes in all directions.
Active Vibration Control of Rectangular Plate with Piezoceramic Elements
Archives of Acoustics, 2008
This paper represents the possibilities of reducing mechanical vibration of plates by active vibration control through piezoceramic elements placed on the plane. In the preliminary research a rectangular plate made of aluminium was analyzed. Sound insulation and vibrations measurement were executed on a specialized enclosure in reverberation chamber. A PZT piezoceramic was proposed to control vibrations of the plate. Piezoelements were located in four points on the plate, which have maximum amplitude for (2,2) mode. Vibrations and transmitted sound before and after control is compared using sound and vibration analyser. The results show that after control, vibrations are reduced 10 dB
Frequency Response Analysis of Hybrid Piezoelectric Cantilever Beam
2010
Frequency response analysis of hybrid aluminium beam with piezoelectric actuators was performed using finite element method. The finite element model was implemented in Matlab software. The one-dimensional beam element is based on Euler-Bernoulli theory and it assumes bilinear distribution of electric field potential. The piezoelectric actuators were driven by harmonic signals around the first eigenfrequency and the beam oscillations were investigated. Results were compared to experiment.
STUDY ON VIBRATION CHARACTERISTICS OF PZT ACTUATED MILDSTEEL AND ALUMINIUM CANTILEVER BEAMS
Considerable attentions have been devoted recently to active vibration control using smart materials as actuators. This study presents an active vibration control technique applied to a smart beam. The smart beam consists of Aluminum and mild steel beams modeled in cantilevered configuration with surface bonded piezoelectric (lead-Zirconium-Titanate-PZT) patches .The natural frequency of smart beams were found using finite element code for first four modes by varying the location of actuator from the fixed end of the structure, and it has good agreement with analytically found natural frequency. An experimental apparatus has been developed to study the vibration suppression of the smart beams. The free vibration of the mild steel and aluminum beams were carried out by varying the initial displacement and input voltage to the PZT in order to find out the settling time and the damping factor of both of the beams. The results shows that the aluminium beam will have little more damping effect than mild steel leads to less settling time of aluminum.
Vibration Analysis and Control of a Piezoelectric Elements Bonded Flexural-Torsional Beam
An analytical method for flexural and torsional vibration analysis of a Euler-Bernoulli beam has been developed as a baseline for treating flexible beam attached to central-body space structure. Extension of this work is carried out for the generic problem of Active Vibration Suppressionof a cantilevered Euler-Bernoulli beam with piezoelectric sensor and actuator attached as appropriate along the beam. Such generic example can be further extended for tackling lightweight structures in space applications, such as antennas, robot's arms and solar panels. For comparative study, three generic configurations of the combined beam and piezoelectric elements are solved. The equation of motion of the beam is expressed using Hamilton's principle, and the baseline problem is solved using Galerkin based finite element method. Nomenclature a,b,c,d = coefficients in the frequency equation C = origin of coordinate system D = shear center e ,s = curvilinear coordinates F = area of cross section f = frequency G = shear modulus K = Saint Venant torsion constant L = length of element M, Mx, My = bending moments Mω = bimoment mx, my, mD, mω= external bending moments, torsional moment and bimoment per unit length of the beam N = axial force O = starting point (point from which s is measured) P = external force px, py, pz = externally loads per unit length of the beam x y z p , p , p = externally applied loads per unit area of midplane of the beam TD = total torsional moment T = torsional momet on the beam Tk = kinetic Energy t = thickness of wall U, V,F = amplitudes of the transverse displacements and torsional rotation U = work of actual stresses u = vector of displacements u, v, w = displacements of shear center