Piezoelectric sensor

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

Finite element simulation of piezoelectric wafer active sensors for structural health monitoring with coupled-filed elements

Abstract: Crack detection with piezoelectric wafer active sensors (PWAS) is emerging as an effective and powerful technique in structural health monitoring (SHM). Modeling and simulation of PWAS and host structure play an important role in the SHM applications with PWAS. For decades finite element method has been extensively applied in the analysis of piezoelectric materials and structures. The advantage of finite element analysis over analytical solutions is that stress and electrical field measurements of complex geometries, and their variations throughout the device, are more readily calculated. FEM allows calculation of the stress and electric field distributions under static loads and under any applied electrical frequency, and so the effect of device geometry can be assessed and optimized without the need to manufacture and test numerous devices. Coupled field analysis taking both mechanical motions and electrical characteristics into account should all be employed to provide a systemic overview of the piezoelectric sensors/actuators (even arrays of them) and the host structures. This use of PWAS for SHM has followed two main paths: (a). Wave propagation (b). Electromechanical impedance; Previous research has shown that PWAS can detect damage using wave reflections, changes in wave signature, or changes in the electromechanical (E/M) impedance spectrum. The primary goal of this paper is to investigate the use of finite element method (FEM) to simulate various SHM methods with PWAS. For the simulation of Electro-mechanical (E/M) impedance technique, simple models, like free PWAS of different shapes and 1-dimmension beam with PWAS are investigated and the simulated structural E/M impedance was presented. For the wave propagation SHM technique, a long beam with several PWAS installed was studied. One PWAS is excited by tone burst signals and elastic wave will propagate along the beam. The existence of a crack will affect the structure integrity and the echo reflected by crack can be observed through the simulations. By using the coupled field elements, direct simulation of electro-mechanical interaction of the PWAS and the host structure was made possible. The electrical potential generated on the PWAS surface by the stimulation of elastic wave can be examined in our FEM analysis. The simulation results are then compared to analytical calculation and experimental data.

Piezoelectric film, piezoelectric element, piezoelectric actuator, piezoelectric pump, ink-jet type recording head, ink-jet printer, surface-acoustic-wave element, thin-film piezoelectric resonator, frequency filter, oscillator, electronic circuit, and electronic apparatus

Abstract: A piezoelectric film is provided having good piezoelectric properties. The piezoelectric film is represented by the following general formula: A1−bB1−aXaO3 wherein A contains Pb; B is at least one of Zr and Ti; X is at least one of V, Nb, Ta, Cr, Mo and W; a satisfies 0.05≦a≦0.3; and b satisfies 0.025≦b≦0.15.

Interlaminar Stress Analysis of Shell Structures with Piezoelectric Patch Including Thermal Loading

Abstract: Interlaminar stress distribution in smart composite shells using a coupled thermal-piezoelectric-mechanical model is investigated. To maintain local accuracy of stress distributions, the trial displacement field is assumed layerwise higher order and C 0 continuous through the entire laminate thickness, accommodating zigzag in-plane warping and interlaminar shear stress continuity. The temperature and electrical fields are modeled using higher-order descriptions that can satisfy surface flux boundary conditions at structural surfaces and equipotential conditions at electrode surfaces. These assumptions ensure computational efficiency. A variational principle, addressing the interaction between thermal, piezoelectric, and mechanical fields, is used to derive the governing equations of equilibrium. The proposed theory is used to investigate the cylindrical bending problem of simply supported composite host structures with attached piezoelectric actuators, subject to a combination of mechanical, piezo-electric, and thermal loading. The interlaminar stress distributions under comprehensive loading are presented for different geometries and stacking sequences. The effects of two-way piezoelectric and thermal coupling on the stress distributions are investigated. The significance of the thermal mismatch effect on interlaminar stress distribution is also discussed. The results from present theory are validated with available exact elasticity solutions.

Impact wave and damage detections using a strain-free fiber Bragg grating ultrasonic receiver

Abstract: A strain-free mobile fiber Bragg grating (FBG) ultrasonic receiver is applied for the impact-related experiments of carbon fiber reinforced plastic laminates. The strain-free FBG sensor detects an impact-induced acousto-ultrasonic wave and its responses are compared with those of a piezoelectric sensor. Ultrasonic mode wavelength-related averaging effect in FBG ultrasonic sensors is also reported. The mobile FBG sensor can be useful for the acoustic characterization and the sensor placement optimization being required before construction of a built-in FBG network. Finally, the mobility of the strain-free FBG sensor head is extended to ultrasonic scanning application. Based on its high scanning spatial resolution, impact damage sizing is conducted more precisely.

Thick-film piezoceramics and devices

Abstract: Over the past 20 years, thick-film (screen printed) technology has been shown to possess a variety of desirable characteristics, which are particularly suitable for the realisation of micro-sensors and actuators. In particular, thick-film sensors are noted for their robust, versatile, compact and inexpensive nature. This paper will describe how screen printed thick-films can be used as the basis for a variety of piezoelectric a transducers. It will be shown how the technology can be combined with MicroElectroMechanical Systems (MEMS) to generate new types of microengineered structure. The evolution of the technology to a successful enabling mechanism for modern-day solid state sensors is described. The paper begins with a brief overview of piezoelectric thick-films including a discussion of the main factors relating to paste formulation, characterisation and techniques for fabricating devices. There is also a description of methods for fabricating thick-films on silicon, which opens up the possibility of using thick-film technology in the field of MEMS. A number of specific sensors and actuators are described, including accelerometers, micropumps, ultrasonic motors, slip sensors for prosthetic hands, resonators, elastic wave sensors and ultrasonic separators.