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Journal Article 5

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piezoelectricity 4

“ 2

E” 2

experiment 2

pump 2

-shaped value 1

-shaped valve 1

Lead-free piezoelectric ceramics 1

NaNbO₃-BaTiO₃ 1

ceramics 1

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crystal structure 1

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deflagration-to-detonation transition 1

flaw detection 1

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Investigations on multicycle spray detonations

LI Mu, YAN Chuanjun, ZHENG Longxi, WANG Zhiwu, QIU Hua

Frontiers in Energy 2007, Volume 1, Issue 2, Pages 207-212 doi: 10.1007/s00000-007-0027-5

Abstract: The average of pressure peak, as measured by piezoelectricity pressure transducer, increased versus distance

Keywords： multicycle deflagration-to-detonation transition pressure transducer compression piezoelectricity pressure

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Novel piezoelectric pump with “E”-shaped valve found from sub-experiments

Jianhui ZHANG, Jun HUANG, Xiaoqi HU, Qixiao XI,

Frontiers of Mechanical Engineering 2010, Volume 5, Issue 2, Pages 212-218 doi: 10.1007/s11465-010-0009-x

Abstract: Increasing the driving frequency of a piezoelectric vibrator can resolve the bottleneck of low flow in a valve piezoelectric pump. However, a piezoelectric pump of a traditional valve body presents the hysteretic nature of the valve, and macroscopic performance is up-frequency to flow-sharply. This research is to settle the bottleneck mentioned above. First, through the sub-experiment on various parameters of the plate valve of a piezoelectric pump, the reasons why a valve body itself can influence “up-frequency to flow-sharply”, which causes the hysteretic nature of the valve, were discovered. Second, an “E”-shaped valve and piezoelectric pump with an “E”-shaped valve (PPEV) were invented. Finally, the efficiency of PPEV has been proved helpful to reduce hysteretic nature in experiments. Under the similar conditions, compared with traditional pumps, the driving frequency of novel PPEV can be more than 10 times high, and the flow rate also can be several times high.

Keywords： piezoelectricity valve pump experiment “ E” -shaped valve

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Microstructure and electrical properties of NaNbO

Shihui XIE, Kongjun ZHU, Jinhao QIU, Hua GUO

Frontiers of Mechanical Engineering 2009, Volume 4, Issue 3, Pages 345-349 doi: 10.1007/s11465-009-0050-9

Abstract: Lead-free piezoelectric ceramics (1- )NaNbO - BaTiO have been fabricated by a traditional ceramic sintering technique. The effects of BaTiO (BT) synthesized by hydrothermal method on crystal structure, density, dielectric, piezoelectric, and electromechanical properties were investigated. Results show that the phase structure transforms from the orthorhombic phase to the tetragonal phase with the increase of the content of BT, and the two phases co-exist when 0.08< ≤0.10. However, the optimum composition for (1- )NaNbO - BaTiO ceramics is 0.90NaNbO -0.10BaTiO . The 0.90NaNbO -0.10BaTiO ceramics sintered at 1250°C have higher properties: piezoelectric constant of 120 pC/N, dielectric constant of 718, planar electromechanical coupling factor of 24%, planar frequency of 3 MHz·mm, and the mechanical quality factor of 138, respectively. The results show that the (1- )NaNbO - BaTiO ceramics is one of the promising lead-free materials for high-frequency applications.

Keywords： Lead-free piezoelectric ceramics NaNbO₃-BaTiO₃ piezoelectricity ceramics crystal

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Machine of testing the ceramic’s bending strength properties at high temperature and ultra-low speed

Jianhui ZHANG, Fang YE, Onuki AKIYOSHI,

Frontiers of Mechanical Engineering 2010, Volume 5, Issue 3, Pages 289-293 doi: 10.1007/s11465-010-0094-x

Abstract: According to the established rules for testing ceramic’s bending strength, the falling velocity of the pressure head of the machine should be more than 0.5 mm/min. For the machine of testing the ceramic’s bending strength properties, most designs adopt the lowest falling velocity as 0.5 mm/min. In the fields such as aerospace and deep-ocean exploration, the utilization of ceramic materials that work at normal temperature, low temperature, or even high temperature and bend at an ultra-low velocity is increasing; thus, the intense requirements for the machine of testing the ceramic’s bending strength properties at high temperature and ultra-low speed (MTCBSP) and its experimental basis are put forward. This research developed an MTCBSP suitable for normal temperature and high temperature with the lowest falling velocity of 0.05 mm/min, and manufactured a drive reducer for ultra-low speed and high-temperature working condition. In the test, equipment includes a high-temperature furnace, bending die for four-point bending, and protection system of inert gas, which was placed in the high-temperature furnace to prevent the ceramic sample from being oxidized to diminish its effects. The results show that the lowest falling velocity of the pressure head of this new machine is 0.05 mm/min, and the mechanical properties of silica glasses are noticeably different at the same high temperature and the different falling velocities of 0.5 mm/min and 0.05 mm/min.

Keywords： piezoelectricity value pump experiment “ E” -shaped value

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Detection of void and metallic inclusion in 2D piezoelectric cantilever beam using impedance measurements

S. SAMANTA, S. S. NANTHAKUMAR, R. K. ANNABATTULA, X. ZHUANG

Frontiers of Structural and Civil Engineering 2019, Volume 13, Issue 3, Pages 542-556 doi: 10.1007/s11709-018-0496-0

Abstract: The aim of current work is to improve the existing inverse methodology of void-detection based on a target impedance curve, leading to quick-prediction of the parameters of single circular void. In this work, mode-shape dependent shifting phenomenon of peaks of impedance curve with change in void location has been analyzed. A number of initial guesses followed by an iterative optimization algorithm based on univariate method has been used to solve the problem. In each iteration starting from each initial guess, the difference between the computationally obtained impedance curve and the target impedance curve has been reduced. This methodology has been extended to detect single circular metallic inclusion in 2D piezoelectric cantilever beam. A good accuracy level was observed for detection of flaw radius and flaw-location along beam-length, but not the precise location along beam-width.

Keywords： piezoelectricity impedance curve mode shapes inverse problem flaw detection curve shifting