Analysis of Rolling Element Bearing Faults Via Curve Length Transform

WOS: 000341192800007This paper aims to present the performance of a simple nonlinear time domain transformation known as Curve Length Transform (CLT) on the detection of rolling element bearing faults. Experimental vibration velocity and acceleration responses collected from a test rig are used to analyze the bearing signals. Artificial defects are introduced on the raceways of inner and outer rings of a deep groove ball bearing to examine different bearing faults. Unbalance load condition is created by attaching an eccentric mass to the rotating shaft in order to analyze the effect of the unbalance load together with the bearing fault on the performance of the curve length transform. Basic temporal indicators such as Root Mean Square (RMS), standard deviation, peak to peak, crest factor and kurtosis derived from the curve length signals are used for defect detection purpose. Time domain analyses based on the experimental measurements show that the curve length transform can be used to enhance the diagnostic capabilities of some time domain indicators.Dokuz Eylul UniversityDokuz Eylul University [2006.KB.FEN.19]The authors express their special thanks to the Rectorship of Dokuz Eylul University for giving support to the research project with project number 2006.KB.FEN.19

Deep learning for automated detection and numbering of permanent teeth on panoramic images

[No Abstract Available

Characterization and analysis of motion mechanism of electroactive chitosan-based actuator

WOS: 000418661000048PubMed ID: 29253989In order to analyze the bending mechanism of the electroactive chitosan- based actuator, different amounts of poly(diallyldimethylammonium chloride) (PDAD) were incorporated in chitosan solution. The effects of PDAD concentration on electromechanical performance of chitosan actuator were investigated under various excitation voltages. With the incorporation of PDAD into chitosan solution, crosslinked chitosan film acts as an actuator showing a considerable displacement behavior. However it can be noted that higher incorporation of PDAD into chitosan solution decreased the performance of the actuators. Thermal, viscoelastic, and crystallographic properties of the chitosan films were examined by thermogravimetric analysis, dynamic mechanical analysis, and X- ray diffraction analysis, respectively. The effect of incorporation of PDAD in chitosan- based film on morphological properties of chitosan film was determined by scanning electron microscopy. It was observed that the films involving PDAD have larger pore size than the PDAD free film.TUBITAK-The Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111M643]This study was supported by TUBITAK-The Scientific and Technological Research Council of Turkey, with a Project Number: 111M643

Electromechanical characterization of multilayer graphene-reinforced cellulose composite containing 1-ethyl-3-methylimidazolium diethylphosphonate ionic liquid

WOS: 000395821600014In this study, multilayer graphene (Gr)-reinforced cellulose composites were synthesized by using 1-ethyl-3-methylimidazolium diethylphosphonate ionic liquid. The composites were fabricated via dissolving the cellulose in 1-ethyl-3-methylimidazolium diethylphosphonate and Gr loading at different ratios (0.2, 0.4, and 0.6 wt.%). Both sides of the composites were coated with gold leaf to generate electrodes. The effect of Gr loading on chemical functional groups, crystallographic properties, thermal stability, and morphological and mechanical properties of cellulose film was investigated by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and tensile test, respectively. Electromechanical behavior of the cellulose composite films reinforced with Gr (0.2, 0.4, and 0.6 wt.%) was investigated under DC excitation voltages of 1, 3, 5 and 7 V. Gr loading of 0.2 wt.% increased maximum tip displacement by 400% when the actuator is excited with 3 V.TUBITAK - The Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111M643]Financial support for this study was provided by TUBITAK - The Scientific and Technological Research Council of Turkey (project number: 111M643)

Electromechanical performance of chitosan-based composite electroactive actuators

WOS: 000377840100014A novel chitosan-based electroactive actuator was fabricated by using chitosan, N, N'-methylenebisacrylamide (MBA), poly (diallyldimethylammonium chloride), and gold metal. The constructive effect of crosslinker to the actuator performance was investigated by using various amounts of MBA. The chitosan-based film samples were characterized using Fourier transform infrared analyses, X-ray diffraction analysis, thermogravimetric analysis, scanning electron microscopy analysis, and tensile test. The viscoelastic properties of films were determined by dynamic mechanical analysis. The motion and force generation capabilities and the repeatability of the actuators were also investigated under electrical stimuli up to 21 V. The suitability of the prepared chitosan-based films to be used as actuator for soft robotic applications is verified experimentally. (C) 2016 Elsevier Ltd. All rights reserved.TUBITAK-The Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111M643]This study was supported by TUBITAK-The Scientific and Technological Research Council of Turkey, Project Number: 111M643

The effect of gold electrode thicknesses on electromechanical performance of Nafion-based Ionic Polymer Metal Composite actuators

WOS: 000462803100068The effect of gold electrode thickness (10, 27, 45, 67 and 80 nm) on the electromechanical performance of Nafion-based Ionic Polymer Metal Composite (IPMC) actuators was investigated in this study. The mechanical, morphological, electrical properties and electroactive behaviors of IPMC under direct current voltage (DC) and alternating voltage (AC) were examined. The tip displacement and maximum blocking force of actuators under various electrical stimulations were measured. In order to define transient response characteristics and quasi steady state value of the actuators, DC excitations of 1, 3, 5, 7 and 9 V were used. Besides, to define bandwidth of the actuator samples, square wave excitation with magnitudes of 3, 5, and 7 V and frequencies of 0.1, 0.25, 0.5, 1, and 2 Hz were applied to actuator samples. The actuator having a gold electrode thickness of 45 nm produced maximum tip displacement among all actuators for all excitation DC voltages. In the square wave experiments, the higher cutoff frequencies were observed for the actuators with 27 and 45 nm electrode thicknesses. The blocking force of IPMC increased with increasing gold electrode thickness from 10 nm to 45 nm and decreased with increasing gold electrode thickness from 45 nm to 80 nm.TUBITAK-The Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111M643]Financial support for this study was provided by TUBITAK-The Scientific and Technological Research Council of Turkey, Project Number: 111M643

Investigation of the effects of PWM parameters on ionic polymer metal composite actuators

WOS: 000341077700039The effects of the PWM excitation signal parameters, such as frequency and magnitude, on the Nafion-based ionic polymer metal composite (IPMC) actuator response were found out. The first set of experiments was designed to observe the actuator response when the actuators were biased with constant DC voltages. These experimental results were exploited to build an experimental data based dynamic model. The model and these results were also used as references to evaluate the experimental results in the proceeding experiments. The second set of experiments was designed to observe the actuator response when the DC square wave signals at different frequencies (0 to 1000 Hz) were applied. The third set of experiments was designed to observe the actuator response when the PWM signals at different magnitudes (6, 8 and 10 V) were applied. It is observed that back relaxation reduces with increasing frequency, but after a certain frequency value, it remains approximately constant. It is seen that the input output relationship of the actuators are linear only for a range of PWM signal magnitudes. The observations in both the PWM frequency and the magnitude experiments indicated that the performance of the Nafion-based IPMC actuator could be improved by selecting a magnitude of PWM signals between 6-8 Volts and by selecting a frequency between 400-1000 Hz.TUBITAK-The Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111M643]Financial support for this study was provided by TUBITAK-The Scientific and Technological Research Council of Turkey, Project Number: 111M643

Effects of PEG loading on electromechanical behavior of cellulose-based electroactive composite

WOS: 000354193000032Electroactive behavior of carboxymethylcellulose (CMC)-based actuators was investigated in this study. CMC-based films were firstly fabricated by using 1-butyl-3-methylimidazolium bromide. Characterization studies of the CMC films were conducted by using Fourier transform infrared, X-ray diffraction analysis, thermogravimetric analysis, scanning electron microscopy, and tensile testing. CMC-based actuator films were produced by gold coating on both surfaces of CMC-based films Polyethylene glycol (PEG) at different loadings (1, 1.5 and 2 g) was used to improve electroactive behavior of CMC based actuators. Maximum tip displacements were obtained under DC excitation voltages of 1, 3, 5 and 7 V. CMC based actuator loaded with 1.5 g PEG exhibited the largest tip displacement among other actuators for each excitation voltage. The PEG loading did not lead to considerable differences in tensile strength of CMC-based films However, Young's modulus decreased with PEG loading.TUBITAK-The Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111M643]Financial support for this study was provided by TUBITAK-The Scientific and Technological Research Council of Turkey, Project Number: 111M643

Investigation of the effects of PWM parameters on ionic polymer metal composite actuators

WOS: 000341077700039The effects of the PWM excitation signal parameters, such as frequency and magnitude, on the Nafion-based ionic polymer metal composite (IPMC) actuator response were found out. The first set of experiments was designed to observe the actuator response when the actuators were biased with constant DC voltages. These experimental results were exploited to build an experimental data based dynamic model. The model and these results were also used as references to evaluate the experimental results in the proceeding experiments. The second set of experiments was designed to observe the actuator response when the DC square wave signals at different frequencies (0 to 1000 Hz) were applied. The third set of experiments was designed to observe the actuator response when the PWM signals at different magnitudes (6, 8 and 10 V) were applied. It is observed that back relaxation reduces with increasing frequency, but after a certain frequency value, it remains approximately constant. It is seen that the input output relationship of the actuators are linear only for a range of PWM signal magnitudes. The observations in both the PWM frequency and the magnitude experiments indicated that the performance of the Nafion-based IPMC actuator could be improved by selecting a magnitude of PWM signals between 6-8 Volts and by selecting a frequency between 400-1000 Hz.TUBITAK-The Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111M643]Financial support for this study was provided by TUBITAK-The Scientific and Technological Research Council of Turkey, Project Number: 111M643