42 research outputs found
Modeling and design optimization of butterfly type piezoelectric actuator
A study of a novel design miniature butterfly type piezoelectric actuator is proposed and analyzed in the paper. Actuator consists of butterfly type oscillator and two piezoceramic elements. Operating principle of the actuator is based on exciting electrodes of the piezoceramic elements using input voltage of the same frequency but different phases. Elliptic trajectory of the contact point movement is achieving when phases of the voltage differ by ?/2 on different electrodes. Numerical modelling and simulation of the piezoelectric actuator was performed using finite element method. Natural frequencies, modal shapes and actuator response to the different input voltage sets were analyzed. Optimization of actuator boundary conditions was carried out. Experimental prototype of the piezoelectric actuator was built and measurements of driven tip movements were performed. The results of numerical and experimental studies are discusse
Rod-shaped piezoelectric actuator with radial polarization
This paper analyzes contact point trajectories of the rod-type piezoelectric actuator, which has circular cross-section and is characterized by the non-uniform polarization. Radial polarization is used to achieve flexural oscillations in perpendicular planes and to increase number of degrees of freedom of the contact point movement. Particular electrode pattern of the actuator was determined and contact point trajectories were studied under different excitation regimes. A prototype of piezoelectric actuator was developed and experimental measurements of contact point trajectories were performed. The results of numerical modeling and experimental study are compared and discussed
New linear piezoelectric actuator based on traveling wave
A novel design of linear type piezoelectric actuator is proposed and analyzed in the paper. Actuator has a beam shape with cut-out hole. Traveling wave is generated on the top area of the actuator applying harmonic oscillations on the ends of the beam. These oscillations are generated by two piezoceramic elements and transferred to the ends of the beam. Electrodes of piezoceramic elements are excited by harmonic voltage with phase difference of ?/2. Numerical modeling based on finite element method was performed to find resonant frequencies and modal shapes of the actuator and to calculate the trajectories of contact point movements under different excitation schemes. A prototype of the piezoelectric actuator was built and measurements of top surface oscillations were performed. Results of numerical and experimental studies are discusse
Research of the flexible bellow with the magnetorheological fluid
MR fluids are widely used in various structures such as controlled dampers, brakes, clutches, etc. Application of these fluids can reduce energy costs and weight as well as increase device operational speed and lifetime. In order to exploit all the qualities of MRS and ERS properties it is necessary to occasionally mix the fluids and monitor them. These systems are still under research and development in laboratories worldwide. This article describes the developed and tested flexible bellow, which can determine whether the MR fluid is under influence of sedimentation and whether it can operate correctly or it is necessary to perform the mixin
Evaluation of the resistance force of magnetorheological fluid damper
The aim of this research was to examine the resistance force generated by linear hydro-cylinder type magnetorheological fluid (MRF) damper acting in different regimes. MRF damper performance has been investigated experimentally by using universal computerized material properties testing machine. Measurements of resistance force have been carried out for different speeds of the damper piston motion under different strength of the magnetic field. Dependences of the force on these parameters (speed and magnetic field strength) have been obtained. It was defined, that the force increases practically linearly when increasing strength of the magnetic field and when increasing piston speed
Miniature rotary tables with piezoelectric hemispheres: research and development
The aim of this research is to develop and investigate two modifications of high resolution miniature rotary tables, based on the transformation of 3D resonant oscillations of hemisphere actuators into continuous or start-stop motion of contacting rotary table. To generate 3D resonant oscillations of the contacting points, the electrodes of the actuators are sectioned into several parts, enabling the generation of traveling wave type higher forms of oscillations. The results of modeling of hemisphere actuators are presented together with experimental investigation of resolution and response time. It is shown that axial oscillations of the table and its torsional oscillations can be generated, extending the functionality of the devices
Modeling and design optimization of butterfly type piezoelectric actuator
A study of a novel design miniature butterfly type piezoelectric actuator is proposed and analyzed in the paper. Actuator consists of butterfly type oscillator and two piezoceramic elements. Operating principle of the actuator is based on exciting electrodes of the piezoceramic elements using input voltage of the same frequency but different phases. Elliptic trajectory of the contact point movement is achieving when phases of the voltage differ by ?/2 on different electrodes. Numerical modelling and simulation of the piezoelectric actuator was performed using finite element method. Natural frequencies, modal shapes and actuator response to the different input voltage sets were analyzed. Optimization of actuator boundary conditions was carried out. Experimental prototype of the piezoelectric actuator was built and measurements of driven tip movements were performed. The results of numerical and experimental studies are discusse
Investigation of novel design piezoelectric bending actuators
Two piezoelectric bending actuators of a novel design are presented and analysed in the paper. Numerical modelling and experimental study of the piezoelectric bending actuators were performed to verify operating principle and to investigate dynamic characteristics of the actuators. Numerical calculations are performed by using finite element method. Results of experimental study of piezoelectric actuators are compared with the results of finite element simulations. Results of the numerical and experimental research are analysed and discussed
R&D of the device for blind to conceive 2D graphical information
Miniature piezoelectric thimble is described and investigated, based on friction control between PC screen and thimble’s contacting surface. The contours of the image on PC screen switch on and off harmonic or non-harmonic electric signals, connected to the electrodes of bimorph piezoelectric transducer, generating bending deformations, affecting friction coefficient. While scanning the PC screen in two directions, these periodic variations of friction coefficient result in oscillations of the fingertip, related to the color or intensity of the image components on the screen. Another three cases of pin’s oscillations normal to finger contacting surface are described
Vibrational method of cleaning of surfaces from homogeneous waste materials
Cleaning of contaminated surfaces is closely related to the study of adhesion forces between particles and the surface. Despite numerous technological advancements, the adhesion of particles and surfaces is a phenomenon that is far from being fully understood. This is due to many factors acting during process, - such as the surface roughness and material type, size, shape, electrostatic properties of particles, etc. A surface cleaning device based on nonlinear vibration of the contact element is presented in this paper. Relationships describing the periodic motion in steady state operating regimes are obtained. Characteristics of motion as functions of the frequency of excitation are investigated. Experimental investigations were performed for the determination of the influence of the cleaning velocity on the vibration frequency. It is shown that this dependence is directly related to adhesion forces between particles and the surface. Test results are in good accordance with theoretical predictions