The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Shuxiang Dong - One of the best experts on this subject based on the ideXlab platform.
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investigation on Resonant Vibration performances of fe doped bisco3 pbtio3 ceramics in high temperature environment
Journal of the American Ceramic Society, 2015Co-Authors: Xiangyu Gao, Shuxiang DongAbstract:The high-temperature performance of a series of Fe-doped BiScO3-PbTiO3 (BSPT) piezoelectric ceramics at the morphotropic phase boundary was investigated. The effects of different Fe contents on the piezoceramics were assessed with regard to variations in structure, morphology, dielectric properties, piezoelectric properties, and high-temperature Resonant Vibration. X-ray diffraction (XRD) results indicated that the Fe-doped BSPT ceramics show a single perovskite structure and that the c/a ratio undergoes a slight increase with increasing Fe concentrations. It was also found that, as the proportion of Fe in the ceramics was increased, the grain size was enlarged somewhat, the dielectric loss (tan δ) decreased, the mechanical quality factor (Qm) was gradually improved, and the Curie temperature (TC) was increased from 426°C to approximately 460°C. Despite these complex effects, it was evident that Fe doping can improve the high-temperature Resonant Vibration performance of BSPT ceramics, and that these materials exhibit stable Resonant Vibration velocities at temperatures as high as 225°C. Our results indicate that Fe-doped BSPT ceramics have the potential to be used as piezoelectric power devices intended for high-temperature environments.
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Investigation on Resonant Vibration Performances of Fe‐Doped BiScO3–PbTiO3 Ceramics in High‐Temperature Environment
Journal of the American Ceramic Society, 2015Co-Authors: Xiangyu Gao, Shuxiang DongAbstract:The high-temperature performance of a series of Fe-doped BiScO3-PbTiO3 (BSPT) piezoelectric ceramics at the morphotropic phase boundary was investigated. The effects of different Fe contents on the piezoceramics were assessed with regard to variations in structure, morphology, dielectric properties, piezoelectric properties, and high-temperature Resonant Vibration. X-ray diffraction (XRD) results indicated that the Fe-doped BSPT ceramics show a single perovskite structure and that the c/a ratio undergoes a slight increase with increasing Fe concentrations. It was also found that, as the proportion of Fe in the ceramics was increased, the grain size was enlarged somewhat, the dielectric loss (tan δ) decreased, the mechanical quality factor (Qm) was gradually improved, and the Curie temperature (TC) was increased from 426°C to approximately 460°C. Despite these complex effects, it was evident that Fe doping can improve the high-temperature Resonant Vibration performance of BSPT ceramics, and that these materials exhibit stable Resonant Vibration velocities at temperatures as high as 225°C. Our results indicate that Fe-doped BSPT ceramics have the potential to be used as piezoelectric power devices intended for high-temperature environments.
Li-hui Chen - One of the best experts on this subject based on the ideXlab platform.
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Resonant Vibration behavior of sn zn ag solder alloys
Journal of Alloys and Compounds, 2004Co-Authors: Jenn-ming Song, Truan-sheng Lui, G F Lan, Li-hui ChenAbstract:Abstract The effects of Ag content on the microstructure and the Vibration deformation properties of a potential lead-free solder, Sn–9Zn–xAg (x=0.5–3.5 wt.%), are examined in this study. Results show that Ag additions gave rise to microstructural changes in Sn–Zn eutectic alloys used, resulting in the appearance of proeutectic Sn-rich dendrites and Ag–Zn intermetallics (e-AgZn3 and γ-Ag5Zn8) which replaced the Zn-rich phase. These microstructural changes strongly affect the Vibration-deformed structure morphology and Vibration properties. When the Ag content is higher than 1.5 wt.%, the specimens possess high damping capacity and thus a long Vibration life. This can be attributed to the proeutectic Sn dendrites improving the damping capacity and Ag–Zn intermetallics increasing Vibration-fracture resistance.
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Effects of Matrix Structure on the Resonant Vibration Behavior of Spheroidal Graphite Cast Iron
MATERIALS TRANSACTIONS, 2004Co-Authors: Jenn-ming Song, Truan-sheng Lui, Li-hui Chen, S. C. Lin, Yu Hua SongAbstract:This investigation examined the Resonant Vibration fracture behaviors of spheroidal graphite (SG) cast iron with various matrix structures. The results show that the Vibration life is determined by a combined effect of the damping capacity and cracking resistance of the matrix. The structure surrounding graphite nodules also plays an important role since the stress concentrates in the vicinity of the nodules during Vibration.
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Resonant Vibration Behavior of Lead-Free Solders
Journal of Electronic Materials, 2003Co-Authors: Jenn-ming Song, Truan-sheng Lui, Li-hui Chen, De-chang TsaiAbstract:This study investigated the Resonant Vibration-fatigue characteristics of some potential lead-free solders, including Sn-Zn, Sn-Ag Sn-Cu, and Sn-Bi alloys. Results show that, under a fixed Vibration force, the damping capacity and Vibration-fracture resistance of Sn-Cu and Sn-Ag eutectic alloys with an off-eutectic structure are higher than Sn-Pb and are also higher than Sn-Bi and Sn-Zn. This is closely related to the Vibration-deformed structure and crack-propagation morphology associated with the microstructural features of the materials. Also, the striated deformation in the Sn-rich phase can be regarded as an effective mechanism in absorbing Vibration energy. Moreover, microstructural modification of the Sn-Zn eutectic alloy can be achieved through Ag addition, and thus, the damping capacity and Vibration-fracture resistance can be significantly improved.
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Roles of matrix structure on Resonant Vibration fatigue fracture of spheroidal graphite cast iron
International Journal of Cast Metals Research, 2002Co-Authors: S. C. Lin, Truan-sheng Lui, Li-hui Chen, Jenn-ming SongAbstract:This study examined how to increase the Vibration fatigue fracture resistance, under Resonant conditions, of spheroidal graphite (SG) cast iron by controlling the matrix structure. Experimental results indicated that variations in the matrix structure slightly influenced Resonant frequency, but significantly dominate the initial deflection amplitude and Resonant Vibration fracture resistance.The Resonant Vibration fracture behaviour of ferritic and pearlitic specimens could be divided into four steps, those are (1) crack initiation, (2) crack linking, (3) major crack formation and (4) major crack propagation along the through-thickness direction. Worthy of noticing is that there is no major crack formation during the fracture process of austempered ductile iron (ADI). In the case of the tempered martensite sample, Resonant Vibration caused an instantly catastrophic failure.In addition, since the tough bainitic matrix can effectively arrest crack propagation, the ADI specimen exhibited the highest vibratio...
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Effect of area fraction and morphology of silicon particles on fracture behaviour of hypoeutectic Al-Si alloys under Resonant Vibration
International Journal of Cast Metals Research, 2001Co-Authors: J. H. Horng, Truan-sheng Lui, Li-hui ChenAbstract:The effect of area fraction and morphology of silicon particles on the fracture behaviour of hypoeutectic Al-Si alloys was studied under Resonant Vibration. Experimental results suggested that vibr...
Jan Becker Hogsberg - One of the best experts on this subject based on the ideXlab platform.
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equal modal damping design for a family of Resonant Vibration control formats
Journal of Vibration and Control, 2013Co-Authors: Steen Krenk, Jan Becker HogsbergAbstract:The principle of equal modal damping is used to give a unified presentation and calibration of Resonant control of structures for different control formats, based on velocity, acceleration–position...
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Resonant Vibration control of three bladed wind turbine rotors
AIAA Journal, 2012Co-Authors: Steen Krenk, Martin Nymann Svendsen, Jan Becker HogsbergAbstract:Rotors with blades, as in wind turbines, are prone to Vibrations due to the flexibility of the blades and the support. In the present paper a theory is developed for active control of a combined set of Vibration modes in three-bladed rotors. The control systemconsists of identical collocated actuator-sensor pairs on each of theblades, and targets a set of three modes constituting a collective mode with identical motion of all the blades, and two independent whirling modes, in which a relative motion pattern moves forward or backward over the rotor. The natural frequency of the collective mode is typically lower than the frequency of the whirling modes due to support flexibility. The control signals from the blades are combined into amean signal, addressing the collective mode, and three components from which the mean signal has be subtracted, addressing the pair of whirling modes. The response of the actuators is tuned to provide Resonant damping of the collective mode and the whirling modes by using the separate resonance characteristics of the collective and the whirlingmodes. In the calibration of the control parameters it is important to account for the added flexibility of the structure due to influence of other nonResonant modes. The efficiency of the method is demonstrated by application to a rotor with 42mblades, where the sensor/actuator system is implemented in the form of an axial extensible strut near the root of each blade. The load is provided by a simple but fully threedimensional correlated wind velocity field. It is shown by numerical simulations that the active damping system can provide a significant reduction in the response amplitude of the targeted modes, while applying control moments to the blades that are about 1 order of magnitude smaller than the moments from the external load.
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Resonant Vibration control of rotating beams
Journal of Sound and Vibration, 2011Co-Authors: Martin Nymann Svendsen, Steen Krenk, Jan Becker HogsbergAbstract:Rotating structures, like e.g. wind turbine blades, may be prone to Vibrations associated with particular modes of Vibration. It is demonstrated, how this type of Vibrations can be reduced by using a collocated sensor–actuator system, governed by a Resonant controller. The theory is here demonstrated by an active strut, connecting two cross-sections of a rotating beam. The structure is modeled by beam elements in a rotating frame of reference following the beam. The geometric stiffness is derived in a compact form from an initial stress formulation in terms of section forces and moments. The stiffness, and thereby the natural frequencies, of the beam depend on the rotation speed and the controller is tuned to current rotation speed to match the resonance frequency of the selected mode. It is demonstrated that Resonant control leads to introduction of the intended level of damping in the selected mode and, with good modal connectivity, only very limited modal spill-over is generated. The controller acts by resonance and therefore has only a moderate energy consumption, and successfully reduces modal Vibrations at the resonance frequency.
Xiangyu Gao - One of the best experts on this subject based on the ideXlab platform.
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investigation on Resonant Vibration performances of fe doped bisco3 pbtio3 ceramics in high temperature environment
Journal of the American Ceramic Society, 2015Co-Authors: Xiangyu Gao, Shuxiang DongAbstract:The high-temperature performance of a series of Fe-doped BiScO3-PbTiO3 (BSPT) piezoelectric ceramics at the morphotropic phase boundary was investigated. The effects of different Fe contents on the piezoceramics were assessed with regard to variations in structure, morphology, dielectric properties, piezoelectric properties, and high-temperature Resonant Vibration. X-ray diffraction (XRD) results indicated that the Fe-doped BSPT ceramics show a single perovskite structure and that the c/a ratio undergoes a slight increase with increasing Fe concentrations. It was also found that, as the proportion of Fe in the ceramics was increased, the grain size was enlarged somewhat, the dielectric loss (tan δ) decreased, the mechanical quality factor (Qm) was gradually improved, and the Curie temperature (TC) was increased from 426°C to approximately 460°C. Despite these complex effects, it was evident that Fe doping can improve the high-temperature Resonant Vibration performance of BSPT ceramics, and that these materials exhibit stable Resonant Vibration velocities at temperatures as high as 225°C. Our results indicate that Fe-doped BSPT ceramics have the potential to be used as piezoelectric power devices intended for high-temperature environments.
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Investigation on Resonant Vibration Performances of Fe‐Doped BiScO3–PbTiO3 Ceramics in High‐Temperature Environment
Journal of the American Ceramic Society, 2015Co-Authors: Xiangyu Gao, Shuxiang DongAbstract:The high-temperature performance of a series of Fe-doped BiScO3-PbTiO3 (BSPT) piezoelectric ceramics at the morphotropic phase boundary was investigated. The effects of different Fe contents on the piezoceramics were assessed with regard to variations in structure, morphology, dielectric properties, piezoelectric properties, and high-temperature Resonant Vibration. X-ray diffraction (XRD) results indicated that the Fe-doped BSPT ceramics show a single perovskite structure and that the c/a ratio undergoes a slight increase with increasing Fe concentrations. It was also found that, as the proportion of Fe in the ceramics was increased, the grain size was enlarged somewhat, the dielectric loss (tan δ) decreased, the mechanical quality factor (Qm) was gradually improved, and the Curie temperature (TC) was increased from 426°C to approximately 460°C. Despite these complex effects, it was evident that Fe doping can improve the high-temperature Resonant Vibration performance of BSPT ceramics, and that these materials exhibit stable Resonant Vibration velocities at temperatures as high as 225°C. Our results indicate that Fe-doped BSPT ceramics have the potential to be used as piezoelectric power devices intended for high-temperature environments.
Andreas Schlachetzki - One of the best experts on this subject based on the ideXlab platform.
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Microelectromechanical Vibration sensor with optical interconnects
IEEE\ ASME Journal of Microelectromechanical Systems, 1998Co-Authors: Erwin Peiner, Andreas Schlachetzki, D. Scholz, Klaus Fricke, Peter HauptmannAbstract:A Resonant Vibration sensor realized using silicon micromachining for wear monitoring of rotating machinery is described. It comprises a mechanical resonator, piezoresistive bridge, and components for fiber-optical signal readout by an infrared light-emitting diode. The performance of the microsystem is demonstrated by its static and dynamical behavior. The results confirm that the described sensor has the potential for on-line Vibration control of rotating machinery operated under the conditions of industrial production.
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A low-frequency micromechanical Resonant Vibration sensor for wear monitoring
Sensors and Actuators A, 1997Co-Authors: Holger Fritsch, Dirk Scholz, Thomas Iwert, Ralf Lucklum, P Hauptmann, Erwin Peiner, Andreas SchlachetzkiAbstract:A micromechanical Resonant Vibration sensor (MRVS) is presented with\na geometrical structure that is designed for the detection of Vibrations\nin the low-frequency range. The MRVS is distinguished from conventional\npiezoelectric and micromechanical acceleration sensors by the utilization\nof the resonance effect. The signal-to-noise ratio increases significantly\nwhen the sensor is excited with the designed frequencies. The Vibrational\nproperties of the MRVS have been investigated in the laboratory.\nExamples of the sensor response to different Vibrational sources\nare analysed under industrial conditions. The capability of the sensor\nprinciple for wear monitoring is discussed.