Piezoelectric sensor

About: Piezoelectric sensor is a research topic. Over the lifetime, 7127 publications have been published within this topic receiving 115903 citations.

Modelling and optimal placement of piezoelectric actuators in isotropic plates using genetic algorithms

Abstract: Theoretical modelling of the vibration of plate components of a space structure incorporating piezoelectric actuators is presented. The equations governing the dynamics of the plate, relating the strains in the piezoelectric elements to the strain induced in the system, are derived for isotropic plates using the Rayleigh-Ritz method. The developed model was used for a simply supported plate. The results show that the model can predict natural frequencies of the plate very accurately. Two criteria for the optimal placement of piezoelectric actuators were suggested using modal controllability and the controllability Grammian. The model was then used to predict the closed-loop frequency response of the plate for active vibration control studies with optimal locations of actuators successfully obtained using genetic algorithms. Significant vibration suppression was demonstrated using optimal actuator placement algorithm developed.

Piezoelectric motor structures

Abstract: A piezoelectric motor, bases on utilization of the reverse piezoelectric effect for continuous conversion of electric power into mechanical energy of rotation of the rotor. The piezoelectric motor includes a rotor and a stator, at least one of them incorporating a vibrator of mechanical oscillation, having a piezoelectric device connected to a voltage source and converting electric power into mechanical vibrations. The piezoelectric motor contains no windings and provides considerable driving torques, owing to the stator and rotor being urged against each other. The structure of the piezoelectric motor is determined by the arrangement of the piezoelectric device in the rotor and stator, the type of oscillation being excited, the shape of the piezoelectric device, the arrangement of its electrodes, their shape and electrical connection, as well as by the polarization of the piezoelectric material. Various combinations of these features offer a great variety of structures and designs of the piezoelectric motors, the piezoelectric motor being supplied from a voltage source with supersonic frequency.

Piezoelectric sensor based nondestructive active monitoring of strength gain in concrete

Abstract: The recent advent of smart materials, such as piezoelectric materials, shape-memory alloys, and optical fibers, has added a new dimension to present structural health monitoring techniques. In particular, the electro-mechanical impedance (EMI) sensing technique utilizing piezoelectric materials has emerged as a potential tool for the implementation of a built-in monitoring system for damage detection of civil structures. However, there is little effort to apply this technique for concrete monitoring. In this study, an effort to extend the applicability of the EMI sensing technique is made for strength gain monitoring of early age concrete. PZT (piezoelectric lead zirconate titanate) patches are employed to sense the EMI signature of curing concrete. A series of experiments was conducted on concrete specimens to verify the applicability of the EMI sensing technique. The results show the excellent potential of the EMI sensing technique as a practical and reliable nondestructive method for strength gain monitoring.

Vibration and Wave Propagation Control of Plates with Periodic Arrays of Shunted Piezoelectric Patches

Abstract: Periodic arrays of shunted, piezoelectric patches are employed to control waves propagating over the surface of plate structures, and corresponding vibrations. The shunted, piezoelectric patches act as sources of impedance mismatch, which gives rise to interference phenomena resulting from the interaction between incident, reflected and transmitted waves. Periodically distributed mismatch zones, i.e., the piezo patches, produce frequency dependent, wave-dynamic characteristics, which include the generation of band gaps, or stop bands in the frequency domain. The extent of induced band gaps depends on the mismatch in impedance generated by each patch. The total impedance mismatch, in turn, is determined by the added mass and stiffness of each patch as well as the shunting electrical impedance. Proper selection of the shunting electric-circuit thus provides control over the attenuation capabilities of the piezo-plate structure, as well as the ability to adapt to changing excitation conditions. Control of wave-propagation attenuation and vibration reduction for plates with periodic, shunted, piezoelectric patches is demonstrated numerically, employing finite-element models of the considered structures.

A Novel Semi-Active Multi-Modal Vibration Control Law for a Piezoceramic Actuator

Abstract: In this paper, a novel semi-active energy rate multi-modal vibration control technique is developed for a piezoceramic actuator coupled to a switching resistor/inductor shunt. The technique works by briefly connecting a resistor/inductor shunt to a piezoceramic actuator in order to apply the necessary signed charge to allow energy dissipation. The switch timing is determined by a control scheme that observes the rate of energy change in controlled modes. The control scheme is developed in the paper, and is simplified to enable practical implementation. This new multi-modal control law is applied to both a simple numerical and an experimental test structure. The results from the numerical and experimental tests show that the energy rate multi-mode control law is able to dissipate energy from one, two and three modes of the flexible structures using a single actuator.