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Purpose. The purpose of the paper is to determine the influence of the geometric parameters of the stator of a linear piezoceramic motor in the form of a piezoceramic plate on the characteristics of its amplitude oscillations. Met...
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Purpose. The purpose of the paper is to determine the influence of the geometric parameters of the stator of a linear piezoceramic motor in the form of a piezoceramic plate on the characteristics of its amplitude oscillations. Methodology. For the research, mathematical modeling in the COMSOL Multiphysics software package was used, taking into account the interrelation of electrostatic and mechanical phenomena. Results. By numerical simulation of the process of operating of a linear piezoceramic motor, a rational ratio of the width to the length of the piezoceramic plate is determined. Originality. The rational value of the thickness h of the piezoceramic plate of the motor is also established. Approximate dependencies are proposed for determining the parameters of the relationship between the geometric dimensions of the piezoceramic plate of a linear piezomotor, which makes it possible to predict its characteristics. The adequacy of calculation models is confirmed by experimental studies. Practical value. The results obtained can be used in the design of piezoceramic motors.
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The agriculture is a sector of the economy aimed at providing the population with food and obtaining raw materials for a number of industries. The agricultural industry is one of the most important sectors and is represented in al...
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The agriculture is a sector of the economy aimed at providing the population with food and obtaining raw materials for a number of industries. The agricultural industry is one of the most important sectors and is represented in almost all countries. The food security of states depends on the state of this industry. The plow is the main tool for cultivating the soil in agriculture. At present, we can observe various improvements in the technology for tillage and harvesting, while the main organ of cultivation has not undergone major changes, except for the introduction of more durable and reliable materials. However, tillage is still one of the most energy intensive operations in modern agricultural production. The use of the latest high-performance machinery and equipment while reducing metal consumption and energy consumption is one of the main objectives of the development of modern engineering. However, in this way there are limitations to the performance of traditional machines, the efficiency of which varies in the range of 0.19-0.38. One of the ways to improve tillage and reduce friction between the soil and the plow consists in the use of vibration technologies, which can have a significant effect. Vibration technique and technology are radically different from traditional prototypes. The use of vibration methods in various spheres of human activities and, in particular, in agriculture offers great prospects for accelerating technological progress on a qualitatively new basis. The aim of the work is to improve the cultivation working bodies by reducing the total amount of traction resistance (friction) of the soil on the surface of the ploughshare and reducing the sticking of the working bodies by using SMART PIEZOCERAMICS and vibration principles. The main features of smart designs are: embedded or surface mounted sensors; built-in or surface-mounted actuators; control element diagrams for the implementation of the monitoring system (which allow to process the data from the sensors to make an appropriate decision). The essence of this technology when used in the cultivation of the soil is as follows. The piezoceramic element is tightly located on the surface of the plow blade. Due to the presence of the piezoelectric element of direct and reverse piezoelectric effect, it can be used as an actuator (vibrator) or sensor. To determine the amplitude of oscillations of a piezoceramic element, numerical simulation has been performed using the COMSOL Multiphysics software package. By mathematical modeling, it has been established that the main resonant frequencies of the developed plow design correspond to 150, 2950, 4750, 6050, 13350, 17950, 18550 Hz. The maximum oscillation amplitude of the plow blade corresponds to a frequency of 18,550 Hz.
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The work is devoted to the investigation of the possibilities of using piezoceramic actuators in small-sized aircrafts. The rational relation of the length to the width of the actuator is determined, which is extremely necessary f...
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The work is devoted to the investigation of the possibilities of using piezoceramic actuators in small-sized aircrafts. The rational relation of the length to the width of the actuator is determined, which is extremely necessary for the design of small-sized aircraft. As a result of the research, mathe matical dependencies were obtained for predicting the amplitude of oscillations depending on the ge ometric dimensions of the piezoelectric plate. The adequacy of model calculations has been confirmed by experimental studies.
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In this article, the authors describe the use of piezoelectric sensors and actuators for the prediction of milling tool stability lobes, since existing methods for predicting tool stability have disadvantages which limit their pra...
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In this article, the authors describe the use of piezoelectric sensors and actuators for the prediction of milling tool stability lobes, since existing methods for predicting tool stability have disadvantages which limit their practical use. An experimental approach is described whereby modal testing is performed using surface-mounted piezoelectric sensors and actuators to generate a prediction of tool instability due to regenerative chatter. The approach is first demonstrated by synthetic modal analysis based upon a finite element model of a cantilever beam. Laboratory tests are then performed on small milling tools, and it is shown that there is good agreement with alternative methods for predicting stability. It is concluded that the proposed technique may be more readily suited to automation, and is more appropriate for use on very small milling tools. (C) 2004 Elsevier Ltd. All rights reserved.
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Three exact solutions to the axisymmetric equations governing axially polarized cylinders are first presented. Two of them are the first terms in Bessel and Fourier series expansions of arbitrary boundary conditions on the flat an...
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Three exact solutions to the axisymmetric equations governing axially polarized cylinders are first presented. Two of them are the first terms in Bessel and Fourier series expansions of arbitrary boundary conditions on the flat and curved surfaces, respectively. The third is needed to model clamped boundaries. Then, it is shown that cylinders with arbitrary length-to-radius ratio and certain uniform boundary conditions can be exactly analysed using only these solutions. Other boundary conditions can be satisfied in an average sense. Numerical results are also presented and they are in good agreement with those obtained using ATILA - a finite element program. The solutions presented here together with other solutions can be used to satisfy arbitrary boundary conditions on all surfaces.
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This paper establishes the experimental observations of the correspondence between the characteristics of piezoceramic materials and the sensitivity of narrow-band frequency hydrophones. The hydrophones realized in the laboratory ...
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This paper establishes the experimental observations of the correspondence between the characteristics of piezoceramic materials and the sensitivity of narrow-band frequency hydrophones. The hydrophones realized in the laboratory are of narrow bandwidth with high sensitivity. They can be successfully utilized in marine communication (voice communication between divers or data transmission) because they are like selective filters for the ultrasonic frequencies. [References: 5]
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In this article, a correlation between microstructure and properties for porous piezoceramics of the composition Pb0.95Sr0.05Ti0.47Zr0.53O3 + 1% Nb2O5 was studied in detail. Experimental samples of porous piezoceramics were obtain...
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In this article, a correlation between microstructure and properties for porous piezoceramics of the composition Pb0.95Sr0.05Ti0.47Zr0.53O3 + 1% Nb2O5 was studied in detail. Experimental samples of porous piezoceramics were obtained using a modified method of burning-out a pore former. Porosity dependences of dielectric, elastic, piezoelectric, and electromechanical coefficients of the porous ceramics in the relative porosity range 0-50% were measured and analyzed. It was revealed that the microstructural features of porous piezoceramics defined the character of the porosity dependences of the dielectric, piezoelectric, and electromechanical properties of porous piezoelectric ceramics.
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In the article the attention is paid to the peculiarities of the construction of small-sized aircraft flying into the air with the help of wings based on the bionic principle – copying movements birds or insects. Micro devices of...
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In the article the attention is paid to the peculiarities of the construction of small-sized aircraft flying into the air with the help of wings based on the bionic principle – copying movements birds or insects. Micro devices of such size and type have a wide range of applications and a number of tasks set before them, such as: pollination of crops, search and rescue operations, observation, as well as monitoring of weather, climate and environment with high resolution. The work has found its application in the design of small-sized aircraft, where piezoceramic plates are used as a driving force. The piezoceramics becomes much more relevant than that of an electric motor, since with the reduced design of a small-sized flying machine built on the basis of an electric motor, it will have to reduce the electromagnetic engine itself, that will lead to a loss in the efficiency factor of the engine and the aircraft in general. The piezoceramic engine is capable of converting electric energy into a mechanical one with a very high operating coefficient, which in some cases amounts to more than ninety percents. In addition, the use of piezoactuators has a number of advantages: operating speed, the development of large forces, the absence of a magnetic field, low energy consumption, no tendency to wear, the ability to work in extreme conditions. When constructing small-sized devices based on piezoceramics, the ratio of the length and width of the piezoceramic plate to its resonant frequency is extremely important. As a result of the research, mathematical dependences have been obtained for predicting the oscillation frequency, depending on geometric dimensions of the piezoelectric plate. The adequacy of the obtained numerical calculations is confirmed by experimental studies.
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This paper presents new techniques under development for monitoring the health and suppressing the vibration of flexible composite structures. The techniques use piezoceramic patches bonded to the structure for actuation and sensi...
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This paper presents new techniques under development for monitoring the health and suppressing the vibration of flexible composite structures. The techniques use piezoceramic patches bonded to the structure for actuation and sensing. Simulations and experiments are presented to demonstrate the utility of the methods for beam and panel structures. Limitations of piezoceramic materials are discussed, and suggestions are given for improving the techniques and for developing new uses of piezoceramic materials and smart structures.
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Current models of non-linear electromechanical behaviours of piezoactuators are mostly intended for actuator configurations where the strain of the piezoelectric material is directly used as the linear output. On the other hand, i...
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Current models of non-linear electromechanical behaviours of piezoactuators are mostly intended for actuator configurations where the strain of the piezoelectric material is directly used as the linear output. On the other hand, in the design of piezoactuators, there exist non-trivial configurations where the internal strains of the piezoelectric materials manifest externally in the form of bending and curving rather than simple elongation or contraction, it is also important to predict the non-linear performance of the actuator based on the design parameters. Therefore, it is the intent of this article to present a model that enables calculation of the quasi-static mechanical response of piezoelectric multilayer actuators in non-trivial configurations. It is based on the polarization hysteresis loop and butterfly curve of its constituent piezoelectric material. Using an energy-based formulation, the model takes into account the non-piezoelectric sections as well as the mechanical boundary conditions of the actuator. Furthermore, a three-layer lead zirconium titanate bimorph with both ends clamped is considered in this study. Model calculation of its relationship between input voltage Vand midpoint vertical displacement X is carried out based on ferroelectric hysteresis data of the bimorph material from the literature. The calculation results are then validated by measurements.
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