Papers by Keyword: Piezoelectric Transducer

Abstract: The aim of this paper was to carry out numerical simulations of structural health monitoring applications for plate structures using the boundary element method (BEM). The fundamental symmetric Lamb mode (S0) is chosen for the SHM applications. The propagation, reflection and diffraction of the S0 mode Lamb wave are modelled using a boundary element formulation based on the plane stress theory. Piezoelectric (PZT) actuators are mounted on plate surfaces to excite the S0 mode wave. A semi-analytical method is adopted to couple the PZT actuators and the host plate. Numerical results show that BEM is a very efficient simulation method for the structural health monitoring of plates.

Abstract: In this paper, the application of the dual boundary element method (DBEM) in the field of structural health monitoring (SHM) is explored. The model involves a 3D host structure, which is formulated by the DBEM in the Laplace domain, and 3D piezoelectric transducers, whose finite element model is derived from the electro-mechanical behaviour of piezoelectricity. The piezoelectric transducers and the host structure are coupled together via BEM variables. The practicability of this method in active sensing applications is demonstrated through comparisons with established FEM and parametric studies.

Abstract: This paper analyses the uncertainty of pressure measurements in-cylinder and in injection pipe conducted during the studies of a compression ignition engine. Type A and type B evaluations were used to determine the uncertainties of the results. The results are presented for the engine running on diesel or bio-fuel and operating under full load conditions. The results of normality tests provide grounds to reject H0 in some cases. Slightly lower standard uncertainty of the maximum pressure measurement calculated using type A evaluation were acquired for the engine running on bio-fuel.

Abstract: In this paper, a boundary element method (BEM) for the time-harmonic analysis of electromechanically (EM) coupled 3D structures is presented. Among the two components of an EM coupled structure, the piezoelectric transducer is modelled by a semi-analytical finite element method (FEM), and the host structure is formulated by the dual boundary element method (DBEM). The analysis of the coupled structure is performed in the Fourier domain. The electromechanical impedance (EMI) of the system is used for the purpose of detecting damages.

Abstract: The discussion in the paper is focused on energy transition efficiency, stiffness and intensity of common piezoelectric transducers in the following aspects. Firstly, we have found out that bridge piezoelectric transducers possess high energy transition efficiency and the similar stiffness to asphalt pavement through comparing and analyzing road performance of several common piezoelectric transducers. Thus, we hold the view that it is applicable for energy collection of asphalt pavement and will be analyzed subsequently. Secondly, we have analyzed energy transition efficiency and stiffness characteristics of arc bridge piezoelectric transducer and rectangular bridge piezoelectric transducer in laboratory test. The results show that, under the same load stress, arc transducers are better than rectangular transducers in terms of energy transition efficiency; but comparing with rectangular transducers, arc transducers are more prone to be destroyed, which is not helpful for bearing traffic load.

Abstract: This paper analyses the behaviour ofpiezoelectric transducer for harvesting energy. The transducer was designedusing different materials for harnessing energy that include Zinc Oxide, LeadZirconate Titanate (PZT-2) and Quartz. The transducer was simulated using thesematerials and the voltage generated from ambient vibrations was analysed. MEMsmodule of COMSOL Multiphysics Simulation software was used to perform thesimulations. Behaviour of different materials towards various frequencies madeknown in this study gives an opportunity to estimate the fabricated device and alsosheds light on prospective applications it fits.

Abstract: In this article the principle of gas squeeze film levitation is described and the main application of it is introduced respectively according to the vibration mode.A new piezoelectric transducer applied for squeeze film bearing which is used for cylindrical shaft and can realize equably circumferential fixed support is proposed, the vibration characteristics of it is studied and the bearing’s loading capacity is tested.

Abstract: In this paper, a technique for the detection and the sizing of cracks on isotropic plate structures is presented. The generation and the reception of the detection signals – Lamb waves – are made possible by piezoelectric transducers. The presence and the length of cracks are found by the method of triangulation using signals scattered by crack tips. The practicability of the technique is then assessed by a numerical experiment.

Abstract: Recently, an integration of wireless sensor network with energy harvesters is getting more interested because it can extend the life time of battery in a sensor node, which is very important in many applications. This paper presents the concept of energy analysis in Zigbee based wireless sensor network, which is powered by a piezoelectric energy harvester to optimize the algorithms used in wireless sensor network. In this work, difference aspects related to piezoelectric energy harvester, characteristic of power consumption in Zigbee based wireless sensor node and concept of optimizing algorithms to balance input and output power in the integrated system are proposed. Keywords: energy harvesting, piezoelectric transducer, Zigbee based wireless sensor network

Abstract: The flat transducer is composed of 1-3-2 piezoelectric composite and copper shell. The structure of transducer was determined according to design requirement and finite element analysis by ANSYS. The transducer was prepared by using a 25mm×25mm×4.8mm 1-3-2 composite chip, rigid foam backing, copper shell, polyurethane layer and acoaxial cable. The voltage response, source level, receiving voltage sensitivity and other performance were measured. The resonant frequency of transducer is 294kHz, the maximum transmitting voltage response is 159.6dB, 3dB bandwidth is 32kHz, source level is 208dB, receiving voltage sensitivity of the transducer is -203 ± 3dB in the frequency range of 50-250kHz frequency, the beam width of -3dB is 11º in the directivity.