Search results for "piezoelectricity"
showing 9 items of 99 documents
Layer-Wise Discontinuous Galerkin Methods for Piezoelectric Laminates
2020
In this work, a novel high-order formulation for multilayered piezoelectric plates based on the combination of variable-order interior penalty discontinuous Galerkin methods and general layer-wise plate theories is presented, implemented and tested. The key feature of the formulation is the possibility to tune the order of the basis functions in both the in-plane approximation and the through-the-thickness expansion of the primary variables, namely displacements and electric potential. The results obtained from the application to the considered test cases show accuracy and robustness, thus confirming the developed technique as a supplementary computational tool for the analysis and design o…
On the harvest of rainfall energy by means of piezoelectric transducer
2013
In this paper a detailed study on the harvest of the energy contained in rainfall by means of piezoelectric transducers is presented. Diverse studies agree on the level of suitable generated voltage on the electrodes of a piezoelectric transducer subjected to rainfall, but a complete characterization on the supplied power is still missing. This work, in order to limit optimistic forecasts, takes into account the behavior of the transducers subjected to real and also artificial rainfall, condition that has shown promising behavior in laboratory. In order to increase the energy harvesting and also define its limits different loads have been taken into account. Only commercial transducers have…
Quartz Crystal Microbalance for Bioanalytical Applications
2001
The quartz crystal microbalance (QCM) was first introduced as a mass sensor in gas phase and in vacuum. Since oscillator circuits capable of exciting shear vibrations of quartz resonators under liquid load have been developed, the QCM became accepted as a new powerful technique to monitor adsorption processes at solid/liquid interfaces in chemical and biological research rendering the method an attractive low-cost alternative for bioanalytic applications. In the last decade, adsorption of biomolecules on functionalized surfaces turned out to be one of the paramount applications of piezoelectric transducers comprising the interaction of DNA and RNA with complementary strands, specific recogn…
Electrooptic coefficient measurements by Mach Zehnder interferometric method: Application of Abelès matrix formalism for thin film polymeric sample d…
2013
Abstract In Mach–Zehnder interferometric (MZI) method for determination of thin organic film electrooptic ( EO ) coefficients r 13 and r 33 critical effects, like multiple internal reflections and sample thickness modulation due to electrostriction and piezoelectricity are usually overlooked. Ignoring these effects may lead to inaccurate calculation of EO coefficients from experimental data by the simplified equations. To describe the influence of the above mentioned effects on the output of a MZI containing a thin film polymer sample we have used the Abeles matrix formalism.
Polymers, Ferroelectric Liquid Crystalline Elastomers
2002
Ferroelectric materials are a subclass of pyro- and piezoelectric materials. They are very rarely found in crystalline organic or polymeric materials because ferroelectric hysteresis requires enough molecular mobility to reorient molecular dipoles in space. So semicrystalline polyvinylidene fluoride (PVDF) is nearly the only known compound. On the contrary, ferroelectric behavior is very often observed in chiral liquid crystalline materials, both low molar mass and polymeric. Ferroelectric LC-elastomers represent an interesting class of material because they combine the ordering of liquid crystalline ferroelectric phases and the rubber elasticity of polymer networks. Switching of the electr…
Complex composite structures with integrated piezoelectric transducers
2016
International audience; Nowadays, in different industrial fields as transport or aerospace, a research effort is conducted to reduce the structural weight. One of the most promising solutions is the use of composite structures due to their high stiffness, their low mass density and their low damping factor. At the same time, there is an intensification of the operational dynamic environment and an increase of durability requirements. These different expectations seem to be contradictory. One solution to manage these points is to design and manufacture smart composite structures with a fully distributed set of integrated piezoelec-tric transducers. These structures are able to modify their m…
Modelling the Electromechanical Impedance Method for the Prediction of the Biomechanical Behavior of Dental Implant Stability
2015
Abstract We propose the electromechanical impedance (EMI) technique to assess the stability of dental implants. The technique consists of bonding a piezoelectric transducer to the element to be monitored. Conventionally, electromechanical admittance is used to diagnose structural damage. In this study, we created a 3D finite element model to mimic a transducer bonded to the abutment of a dental implant placed in a host bone site. We simulated the healing after surgery by changing the Young's modulus of the bone-implant interface. The results show that as the Young's modulus of the interface increases, the electromechanical characteristic of the transducer changes.
BEM analysis of a piezoelectric structural health monitoring system for delamination detection
2013
In the present work a piezoelectric based structural health monitoring (SHM) system is analyzed with the aim of assessing the ability of the piezoelectric patch to detect both edge and embedded delaminations proper of flange-skin composite laminated structures. he boundary element model is developed for piezoelectric solids and is implemented by taking advantage of the multidomain technique to model laminated and cracked configurations. A non-linear spring model interface is then implemented in conjunction with an iterative procedure allowing for the simulation of the finite stiffness of the bonding layers as well as of the non-penetration condition of the delamination surfaces. he dynamic …
On the use of the EMI for the health monitoring of bonded elements
2014
The low weight, robustness and fatigue resistance of adhesive joints make them suitable for structural joints. A fully developed nondestructive evaluation technique however is needed to monitor and assess the quality of bonded joints. In the present paper the application of the electromechanical impedance (EMI) technique is proposed. In the EMI method a piezoelectric transducer (PZT) is attached to the structure of interest. The high sensitivity and low power consumption make the EMI method feasible for real time structural health monitoring. In this study we investigated the sensitivity of the electromechanical response of a PZT to the curing and the quality of the adhesive used for bonded…