Papers by Keyword: Transducer

Abstract: This paper presents the methodology of designing a transducer for the experimental measurement of forces. For this purpose, an elastic element of the shape of the letter "S" is designed and manufactured. The elastic element designed in SolidWorks is subjected to virtual testing, using the finite element method in ANSYS. After validating the results obtained considering the maximum values ​​of the stresses that appear for the nominal load, the experimental model of the transducer is realized. The central part of the elastic element behaves like a fixed double beam subjected to bend by the measuring force. On this beam are bonded strain gauge transducers, which measure the deformations produced by bending. The transducer is calibrated, in order to obtain the calibration constant, based on the obtained characteristic, that is, the dependence of the specific strain-deformation and force. The transducer thus constructed can be used in force measurement applications.

Abstract: Silver nanoparticles (Ag NPs) are embedded in Er³⁺/Nd³⁺ co-doped lithium niobate tellurite glasses of the form (68-x)TeO₂-15Li₂CO₃-15Nb₂O₅-1Er₂O₃-1Nd₂O₃-(x)AgCl with x = 1,2 and 3 mol% via conventional melt-quenching technique. The ultrasonic attenuation shows the rate of sound energy reduction when an ultrasonic wave is propagating in a medium which is the lithium niobate tellurite glasses. The glass attenuation depends on the grain size, viscous friction, crystal structure, porosity and hardness. The existence of Ag NPs with an average size of 3.7 nm is confirmed using TEM analysis.

Abstract: Innovation in nanoscience depends fully on the ability to synthesize nanomaterials as well as to assemble them efficiently into complex architectures. The discovery of graphene and graphene polymer nanocomposites is playing a key role in modern nanoscience and nanotechnology. Graphene oxide (GO), is a derivative of graphene obtained by the use of strong oxidizing agents to obtain graphene oxide, a nonconductive hydrophilic carbon material. Synthesis of graphene oxide was performed using the Hummers method. Graphene oxide was integrated into the polysulfone (PSF) matrix to form polysulfone/graphene oxide nanocomposite. Polysulfone casting suspension was prepared by dissolving polysulfone in N,N-dimethyl acetamide. The polymer composites consisted of homogeneously blended polysulfone and graphene oxide casting solutions and drop coated onto boron-doped diamond electrodes (BDD). Interfacial electrochemical dynamics were characterised using cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS). Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy were used to study the morphology and structure of the prepared materials. Modifying with polysulfone blocks electron transfer in the redox reaction of K₃Fe(CN)₆. PSF /GO enhances electron transfer even when compared to bare BDD. The diffusion coefficient and sensitivity for PSF-GO/BDD electrode was calculated to be 2.660 x10^-4 cm² s^-1 and 6.7587 x10^-6 mV s^-1 / A.

Abstract: In this paper a novel concept of the MFC based IDT, Tunable Interdigital Transducer (T-IDT), is presented. The proposed transducer is the extension of the MFC based IDT, where the solid comb electrodes are replaced by series of discrete, stripe electrodes which can be connected independently into the groups and connected to the power source. The span between the centers of the electrodes' groups connected to the same phase are corresponding to the nominal wavelength of the wave excited by the transducer. This makes possible matching to different wavelengths without a need of physical changes of the electrodes’ layout.

Abstract: The paper presents a stage of the research concerning the development and improvement of a low cost small flexible coordinate measuring machine (CMM) that could be used in the future both in research and industry. Its main advantage could refer to the low cost (only about 30 ÷ 40% of the cost of a CMM in the category on the market, having similar dimensions) in conditions of high performance criteria. This could be possible due to the fact that they were implemented some recycled components in the construction of the robotic drive axes of the machine structure, low cost scanning devices and low cost mechanical systems for fixing and adapting the scanning devices. The research stage presented in the paper is essential for the later stages of research to develop an integrated concept: low-cost, flexibility, precision and efficiency, all criteria referring to a small portable scanning CMM, with possible application in any domain. Specifically, the described research stage refers to evaluate the implementation of some scanning systems, type non-contact low-cost and modern displacement transducers, on the principle of emission of LASER radiation, in terms of scanning accuracy. The reason is that currently these systems are used more and more in the CMMs construction.

Abstract: The article discusses the results of experiments on the further development of the method for monitoring the state of the small samples of resin and polymers during curing. The applied method is based on a change in the structure of oscillating transducers leading to variations in the form and/or mode of oscillation. The thin layer of epoxy resin was placed between two piezoelectric transducers in the form of piezoceramic plates. Curing epoxy resin forms a bimorph and its characteristics change along with variations in viscosity or, after the gel point, stiffness. It is possible to establish the level of epoxy resin curing by monitoring changes in the resonance parameters of bimorph elements. The main purpose of cure monitoring of small samples is to develop a new method for evaluating the parameters of resin both before and after the gel point thus taking into consideration that the use of rheological data measured with reference to small samples will be applied for designing or interpreting bulk-flow processes where epoxy may be considered a continuum.

Abstract: Recently, intensive research activity in the application of guided waves (GWs) for structural health monitoring (SHM) has been observed. Interdigital Transducer (IDT) is one of the types of transducers used for generating GWs. The main advantages of such transducers include their ability in generating directional and mode-selective waves. The parameters of IDTs have to be adjusted for the excited wavelength. Some geometric parameters as well as the properties of materials used for manufacturing transducers may be defined using widely known analytical relationships [1]. However, in order to accurately determine the parameters of the IDT, numerous simulations and their experimental verification are required [2]. The paper presents a novel, time efficient approach to the virtual prototyping of complex shaped transducers. The proposed procedure consists of the following four steps: (1) designing a transducer based on analytical relations, (2) approximate numerical simulations of designed transducers with a custom-made, computationally efficient code for screening tests, (3) detailed numerical tests employing the multiphysics Finite Element Method (FEM) for the developed IDT design and (4) experimental tests.

Abstract: Materials with magnetic shape memory gained recognition for their greatest elongation in a group of smart materials, which reaches 10%; another advantage is high operating frequency. Disadvantages must also be considered, these are hysteresis, temperature sensitivity, other nonlinearities and high price. High strain makes it possible to use these materials in actuators design, but it is also possible to apply MSMA in energy harvesters and sensors. This article is linkage between physico-chemical R&D work and basic design of a transducer. Design of a test stand was described, different research scenarios were presented and to sum up this work graphs with the obtained results were placed.

Abstract: Large fluctuation of wind not only make bigger change in turbine output, which may cause talkaround of wind turbine and threaten the safety of the grid. The article studied the wind disturbance problem of DFIG by simulation.The transducer used in article all have vector control and propeller pitch control. The article has some reference function to the related study.

Abstract: Transducer with large directivity and high transmitting sensitivity is designed and fabricated. It is a sandwich transducer with composite horn and it has a finite baffle. A novel model considering the dimension of baffle is deduced, the directivity of transducers are calculated under different conditions. The computations of models agree with the experimental data well. The maximum transmitting voltage response level of the sandwich transducer is 143dB (1V/μPa) and the directivity is up to 99°(-3dB) at the resonance frequency of 75.6kHz.