scholarly journals Modelling vibrations of axial piezoelectric generator with active base

2021 ◽  
Vol 2131 (2) ◽  
pp. 022018
Author(s):  
R K Haldkar ◽  
I A Parinov ◽  
A V Cherpakov ◽  
O V Shilyaeva
Keyword(s):  
Proof Mass ◽  
Mechanical Vibration ◽  
Electrical Energy ◽  
Cylindrical Shape ◽  
Frequency Range ◽  
Piezoelectric Generator ◽  
Piezoelectric Elements ◽  
Compressive Loads ◽  
Output Characteristics ◽  
Active Base

Abstract Modelling of an axial-type piezoelectric generator (PEG) is considered. PEG is an integral part of the system for converting mechanical vibration energy from the environment into electrical energy. The energy generator has an axial type of the configuration of elements, aimed on using bending and compressive loads simultaneously on piezoelectric elements. The base of the generator is made as an active pinching. A feature of PEG is that the generator has two types of piezoelectric elements: (1) elements located on the substrate in the form of a bimorph and (2) piezoelectric elements of a cylindrical shape, fixing the generator base, located on the same axis. PEG has a symmetrical structure about the center of proof mass. The results of modal and harmonic analysis of vibrations are given for vibration excitation of the PEG base in a certain frequency range. The analysis of the output characteristics is given.

scholarly journals NUMERICAL MODELLING OF OSCILLATING FLOW FOR ENERGY HARVESTING

2021 ◽  
Vol 2021 (6) ◽  
pp. 5360-5365
Author(s):  
TOMAS BLEJCHAR ◽  
◽  
SYLVA DRABKOVA ◽  
VACLAV JANUS ◽  
◽  
...  
Keyword(s):  
Flow Rate ◽  
Volume Flow Rate ◽  
Electrical Energy ◽  
Maximum Energy ◽  
Oscillating Flow ◽  
Cfd Simulations ◽  
Fluidic Oscillator ◽  
Microelectronic Devices ◽  
Piezoelectric Elements ◽  
New Generation

The energy efficiency of systems, equipment, and sensors is nowadays intensively studied. The new generation of microelectronic sensors is very sophisticated and the energy consumption is in the microwatts range. The energy to power the microelectronic devices can be harvested from oscillating flow in small size channels and so replaceable batteries could be eliminated. Piezoelectric elements can convert energy from oscillation to electrical energy. This paper focuses on the simulation of periodic flow in the fluidic oscillator. CFD simulations were performed for several values of the flow rate. Experimental measurement was carried out under the same conditions as the CFD experiment. The main monitored and evaluated parameters were volume flow rate and pressure loss. Fluid oscillations were analysed based on CFD simulations and the theoretical maximum energy available for the deformation of piezoelectric elements and transformable into electrical energy was evaluated.

scholarly journals Experimental-Numerical Design and Evaluation of a Vibration Bioreactor Using Piezoelectric Patches

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 436 ◽  
Author(s):  
David Valentín ◽  
Charline Roehr ◽  
Alexandre Presas ◽  
Christian Heiss ◽  
Eduard Egusquiza ◽  
...  
Keyword(s):  
Numerical Model ◽  
Mechanical Vibration ◽  
Cell Types ◽  
Experimental Results ◽  
Cell Behavior ◽  
Frequency Range ◽  
Piezoelectric Patch ◽  
Numerical Design ◽  
Vibration Pattern

In this present study, we propose a method for exposing biological cells to mechanical vibration. The motive for our research was to design a bioreactor prototype in which in-depth in vitro studies about the influence of vibration on cells and their metabolism can be performed. The therapy of cancer or antibacterial measures are applications of interest. In addition, questions about the reaction of neurons to vibration are still largely unanswered. In our methodology, we used a piezoelectric patch (PZTp) for inducing mechanical vibration to the structure. To control the vibration amplitude, the structure could be excited at different frequency ranges, including resonance and non-resonance conditions. Experimental results show the vibration amplitudes expected for every frequency range tested, as well as the vibration pattern of those excitations. These are essential parameters to quantify the effect of vibration on cell behavior. Furthermore, a numerical model was validated with the experimental results presenting accurate results for the prediction of those parameters. With the calibrated numerical model, we will study in greater depth the effects of different vibration patterns for the abovementioned cell types.

scholarly journals Electromechanical Dynamics Model of Ultrasonic Transducer in Ultrasonic Machining Based on Equivalent Circuit Approach

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1405
Author(s):  
Jian-Guo Zhang ◽  
Zhi-Li Long ◽  
Wen-Ju Ma ◽  
Guang-Hao Hu ◽  
Yang-Min Li
Keyword(s):  
Removal Rate ◽  
Ultrasonic Transducer ◽  
Mechanical Vibration ◽  
Electrical Energy ◽  
Structure Design ◽  
Machining Process ◽  
Ultrasonic Machining ◽  
Impedance Model ◽  
Impedance Characteristics ◽  
Electromechanical Dynamics

Ultrasonic transducer is a piezoelectric actuator that converts AC electrical energy into ultrasonic mechanical vibration to accelerate the material removal rate of workpiece in rotary ultrasonic machining (RUM). In this study, an impedance model of the ultrasonic transducer is established by the electromechanical equivalent approach. The impedance model not only facilitates the structure design of the ultrasonic transducer, but also predicts the effects of different mechanical structural dimensions on the impedance characteristics of the ultrasonic transducer. Moreover, the effects of extension length of the machining tool and the tightening torque of the clamping nut on the impedance characteristics of the ultrasonic transducer are investigated. Finally, through experimental analysis, the impedance transfer function with external force is established to analyze the dynamic characteristics of machining process.

Optimizing Energy Output of Piezoelectric Microcantilevers

2011 ◽  
Author(s):  
Mehdi Rezaeisaray ◽  
Don Raboud ◽  
Walied Moussa
Keyword(s):  
Output Voltage ◽  
Proof Mass ◽  
Geometry Optimization ◽  
Electrical Energy ◽  
Electrical Circuit ◽  
Energy Output ◽  
Test Cases ◽  
New Methods ◽  
Piezoelectric Cantilever ◽  
Piezoelectric Cantilevers

This work presents some new methods in optimizing electrical energy, harvested using a micro piezoelectric cantilever. Both mechanical and electrical aspects have been considered. Mechanically, two items have been considered to maximize the generated voltage: geometry of the cantilever and placement of the electrodes. It has been shown that for given sizes of length and width of the harvester and for a given natural frequency, the output voltage can be increased by adjusting the thickness of the beam and the proof mass and consequently increasing the amplitude of vibration. As well, the placement of the electrodes plays a very important role in optimizing output voltage. It has also been shown that piezoelectric cantilevers with shorter top electrodes induce higher voltage than cantilevers with longer top electrodes. Overall results agree with the analytical equations reported in literature so far. Moreover, distribution of top electrodes along the width of the cantilever has been taken into consideration. It has been shown how output voltage can be approximately doubled by using two narrower top electrodes along the width of the cantilever. All analysis in this work was carried out in ANSYS. In this research, to improve the electrical efficiency, diodes have been considered in the circuit to reduce electrical losses in comparison to rectifiers which have been used in conventional harvesters. Applying these methods to particular test cases, a 71% increase in output voltage was observed for the case of geometry optimization, a 116% increase was observed for the case of shortening the top electrode and losses in the electrical circuit were reduced by approximately 50% by using diodes comparing to using rectifiers. While these results focused on cantilever based harvesters, the ideas contained are equally applicable to other structures.

Modeling and optimization of a wide-band piezoelectric energy harvester for smart building structures

2020 ◽  
Vol 11 (02) ◽  
pp. 2050009
Author(s):  
Prateek Asthana ◽  
Gargi Khanna
Keyword(s):  
Resonant Frequency ◽  
Energy Harvester ◽  
Proof Mass ◽  
Mechanical Energy ◽  
Wide Band ◽  
Electrical Energy ◽  
Sensor Nodes ◽  
Ambient Vibrations ◽  
Band Energy ◽  
Piezoelectric Energy

Piezoelectric energy harvesting refers to conversion of mechanical energy into usable electrical energy. In the modern connected world, wireless sensor nodes are scattered around the environment. These nodes are powered by batteries. Batteries require regular replacement, hence energy harvesters providing continuous autonomous power are used to power these sensor nodes. This work provides two different fixation modes for the resonant frequency for the two modes. Variation in geometric parameter and their effect on resonant frequency and output power have been analyzed. These harvesters capture a wide-band of ambient vibrations and convert them into usable electrical energy. To capture random ambient vibrations, the harvester used is a wide-band energy harvester based on conventional seesaw mechanism. The proposed structure operates on first two resonant frequencies in comparison to the conventional cantilever system working on first resonant frequency. Resonance frequency, as well as response to a varying input vibration frequency, is carried out, showing better performance of seesaw cantilever design. In this work, modeling of wide-band energy harvester with proof mass is being performed. Position of proof mass plays a key role in determining the resonant frequency of the harvester. Placing the proof mass near or away from fixed end results in increase and decrease in stress on the piezoelectric layer. Hence, to avoid the breaking of cantilever, the position of proof mass has been analyzed.

Modeling and Simulation of Monocrystal Piezoelectric Generator

2013 ◽  
Vol 785-786 ◽  
pp. 1203-1207
Author(s):  
Lei Zhang ◽  
Li Qing Fang ◽  
De Qing Guo ◽  
Yong Chao Chen
Keyword(s):  
Modeling And Simulation ◽  
Numerical Method ◽  
Analytical Model ◽  
Piezoelectric Materials ◽  
Mechanical Vibration ◽  
Adhesive Layer ◽  
Operation Mechanism ◽  
Material Parameters ◽  
Voltage Stress ◽  
Piezoelectric Generator

The expressions of voltage, stress and amount of charge of monocrystal piezoelectric generator under concentrated exterior pressure was derived in order to proving the precision and validity of numerical method applied to piezoelectric materials' distribution sensing and the study of operation mechanism ignore the influence of adhesive layer. An analytical model of the monocrystal piezoelectric generator was established by using the mechanical vibration theory. And the effects of the structural and material parameters on the output energy are analyzed.

Nonlinearity in the Dynamic Properties of Vulcanized Rubber Compounds

1954 ◽  
Vol 27 (1) ◽  
pp. 209-222 ◽  
Author(s):  
W. P. Fletcher ◽  
A. N. Gent
Keyword(s):  
Simple Shear ◽  
Dynamic Modulus ◽  
Dynamic Properties ◽  
Mechanical Vibration ◽  
Frequency Range ◽  
Vulcanized Rubber ◽  
Rubber Compounds ◽  
Chemical Combination ◽  
Wide Range ◽  
Static Shear

Abstract Measurements are described of the dynamic properties of rubber, loaded with various amounts and types of filler, when subjected to mechanical vibration in simple shear at amplitudes from 0 to 3 per cent shear in the frequency range 20 to 120 c.p.s. The decrease of dynamic modulus with increasing amplitude is shown, for a wide range of filler types and concentrations, to be determined by the amount of stiffening produced by the filler. This relationship is not influenced by variations in the vulcanizing ingredients, reasonable variations in state of vulcanization, addition of softener, or imposition of static shear strain. Rubber compounds stiffened by mixture with, or chemical combination of, other polymers exhibit a smaller order of nonlinearity than that described above and also exhibit much lower hysteresis values within the amplitude range 0 to 3 per cent shear.

scholarly journals Connected Vibrating Piezoelectric Bimorph Beams as a Wide-band Piezoelectric Power Harvester

2008 ◽  
Vol 20 (5) ◽  
pp. 569-574 ◽  
Author(s):  
Zengtao Yang ◽  
Jiashi Yang
Keyword(s):  
Exact Analytical Solution ◽  
Mechanical Vibration ◽  
Flexural Vibration ◽  
Wide Band ◽  
Electrical Energy ◽  
Vibration Energy ◽  
Piezoelectric Bimorph ◽  
Near Resonance ◽  
Beam Equations ◽  
Power Harvester

We analyze coupled flexural vibration of two elastically and electrically connected piezoelectric beams near resonance for converting mechanical vibration energy to electrical energy. Each beam is a so-called piezoelectric bimorph with two layers of piezoelectrics. The 1D equations for bending of piezoelectric beams are used for a theoretical analysis. An exact analytical solution to the beam equations is obtained. Numerical results based on the solution show that the two resonances of individual beams can be tuned as close as desired by design when they are connected to yield a wide-band electrical output. Therefore, the structure can be used as a wide-band piezoelectric power harvester.

Truss Structure Health Monitoring Based on Electromechanical Impedance Method

2013 ◽  
Vol 330 ◽  
pp. 357-363
Author(s):  
Cun Fu He ◽  
Xiao Ming Cai ◽  
Shen Yang ◽  
Zeng Hua Liu ◽  
Bin Wu
Keyword(s):  
Neural Network ◽  
Health Monitoring ◽  
Truss Structure ◽  
Truss Structures ◽  
Impedance Method ◽  
Nonparametric Model ◽  
Impedance Spectra ◽  
Frequency Range ◽  
Electromechanical Impedance ◽  
Piezoelectric Elements

Truss structure is widely used in civil engineering applications for its advantages of easy transportation, convenient assembly and uniform loading. However, it is difficult to achieve real-time health monitoring because of connection diversity and complexity of truss structures. As a novel structural health monitoring technique, electro-mechanical impedance method could monitor the health state of one structure by measuring the spectra of impedance or admittance of the piezoelectric elements, which are bonded on the surface of this structure. This approach has the advantages of nonparametric model analysis, easy sensor installation and high local sensitivity, especially in sensitive frequency range. The damage information, which is tested and recorded by using electromechanical impedance method, could convert into intuitive results through neural network because of its good ability for nonlinear mapping. In this paper, a three-layer assembly truss structure was chosen as experimental object, piezoelectric elements were bonded on structure joints to measure structural impedance spectra, the change of these structural impedance spectra was tested and recorded under high frequency excitations when different truss bars were loosed, and then, one back-propagation (BP) neural network was built and trained by this damage information, which were treated as input samples. These results show that the sensitivity of impedance method is not the same to different frequency range and trained neural network could quickly identify loosen truss bars.

scholarly journals Properties of Car-Embedded Vibrating Type Piezoelectric Harvesting System

2021 ◽  
Vol 11 (16) ◽  
pp. 7449
Author(s):  
Bo-Gun Koo ◽  
Dong-Jin Shin ◽  
Dong-Hwan Lim ◽  
Min-Soo Kim ◽  
In-Sung Kim ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Energy Conversion ◽  
Mechanical Energy ◽  
Variable Mass ◽  
Electrical Energy ◽  
Engine Block ◽  
Operating Frequency ◽  
Maximum Displacement ◽  
Serial Connection ◽  
Piezoelectric Generator

We investigated the harvesting performance of a double piezoelectric generator, which was embedded into the engine block of a small passenger car. The resonance frequency is approximately between 37 and 52 Hz, where the cantilever showed maximum displacement. In reality, the cantilever has a vibrating characteristic, which dramatically reduces displacement, even when the operating frequency deviates slightly from the resonance frequency. To acquire a large mechanical energy-to-electrical energy conversion, a multiple-piezoelectric generator was employed to absorb the energy even when the vibration switched from a resonance to a non-resonance frequency. In this study, a variable mass box was designed and installed in the engine block of a car. The variable mass box consisted of the serial connection of two masses with different weights. The operating frequency deviated from a resonance to a non-resonance frequency within a few hertz (3~4 Hz); the reduction in vibration was lower, leading to a significant acquisition of the resulting power. This is due to the variable matching of the generator, realized by the action of dual mass. This type of generator was installed in the engine block and produced up to 0.038 and 0.357 mW when the engine was operating at 2200 and 3200 rpm, respectively.

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