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1

Experimental and Simulation Investigations of the Cantilever Beam Energy Harvester

Nowak R.

Machine Dynamics Research

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2017

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Vol. 41, No. 3

95--103

EN

Machines, cars and other constructions often generates harmful vibrations, which can be used as the excitement signal for the energy harvesting structures. Waste mechanical energy can be converted into the electrical energy using piezoelectric element. The harvester described in the present paper consists of cantilever steel beam with both side glued piezoelectric elements. The excitation is realized as a support harmonic movement, where the amplitude is assumed as constant. Two types of research methods are used: experiment and finite element simulations. In the first one method the harvester is attached to the electrodynamic shaker. The generated voltage and acceleration of the selected point are measured. The finite element model is proposed with material and geometrical parameters similar to the laboratory examined harvester. Also, the generator patch model takes into account the three-dimensional piezoelectric effect instead of one-dimensional, which are popular especially in mathematical modeling. The major case specified in this paper is comparison of the experiment and FEM calculations results, what ensures the correctness of the FE model. The acquired amplitude frequency and time domain characteristics of the displacement and the generated voltage are compared and discussed. The proposed and verified FE model will be used in more advanced simulations.

2

Evaluation of the energy harvestable from an airless tire equipped with piezoelectric bimorphs on the lamellar spokes

Suciu C. V., Koyanagi K.

Journal of Telecommunications and Information Technology

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2013

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nr 4

79--84

EN

In this work, one evaluates the electrical power generated by an airless tire equipped with piezoelectric bimorphs on both lateral surfaces of the radially distributed lamellar spokes. Such sheet-like spokes are hinged both toward the wheel drum at the inner annular band, and toward the wheel tread at the outer annular band. Since the hinged spokes are able to transmit tension forces but unable to transmit compression forces, bending and buckling of the spokes occur in the region of contact between the tire and the road. Models for the rolling friction of the airless tire, for the bending and buckling deformation of the spokes, and for the electrical power generated by the airless tire are suggested. Variation of the curvature radii and bending deformations for the spokes in the region of contact with the road are illustrated for various values of the rolling friction coefficient and spoke length. Then, variation of the generated electrical power versus the length of contact is obtained for various travel speeds of the vehicle. One observes that the generated electrical power increases at augmentation of the rolling friction coefficient, spoke length and travel speed. Although the obtained electrical power for the proposed harvesting system is relatively modest, it is not depending on the road roughness, i.e. harvesting becomes possible even on smooth roads, such as highway surfaces.

3

Stiffness analysis of electromechanical transducer for nozzle flapper piezoelectric servo valve

Zhou M., Gao W., Yang Z.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 9b

196-199

EN

An electromechanical transducer is designed to replace the torque motor in the traditional nozzle flapper servo valve. The electromechanical transducer is constructed by two identical piezoelectric bimorphs and a beryllium bronze board. The stiffness values are obtained respectively by theory, simulation and experiment. Comparison and analysis results of the stiffness values prove that the proposed electromechanical transducer can provide a bigger stiffness and meet the requirements of the nozzle flapper piezoelectric servo valve.

PL

Przedstawiono elektromechaniczny przetwornik zaprojektowany z myślą o zastąpieniu silnika w układach serwomechanizmu. Przetwornik składa się z dwóch identycznych bimorfów piezoelektrycznych na podłożu z brązu berylowego.