MECHANICAL MODELING AND EXPERIMENTAL VALIDATION ON PIEZOCERAMIC BASED ON THE SURFACE-BONDED PZT SENSOR

2019 ◽  
Vol 26 (06) ◽  
pp. 1850209
Author(s):  
YANYU MENG ◽  
SHI YAN ◽  
XIAOLONG WEN
Keyword(s):  
Output Voltage ◽  
Excitation Frequency ◽  
Adhesive Layer ◽  
Signal Acquisition ◽  
Mechanical Modeling ◽  
Signal Loss ◽  
Harmonic Force ◽  
Force Amplitude ◽  
Sensor Modeling ◽  
Better Than

This paper proposes the modified mechanical and mathematical modeling of lead zirconium titanate (PZT) sensor based on the PZT constitutive relation in order to solve the complicated boundary condition and stress situation of PZT sensor due to the effect of adhesive-layer damping. The experimental study on the surface-bonded PZT sensor is chosen to carry out the correctness of the proposed models. The results show that the PZT sensor modeling is simplified to three types. When the amplitude of harmonic force is constant, the greater the excitation frequency, the more sensitive the output voltage is, the easier the signal acquisition is. At a certain frequency, the voltage output is proportional to the force amplitude. The larger the area or thickness of PZT, the greater the output voltage is, the more sensitive the signal output is. The output voltage is in quadratic relation to the bonding thickness. Furthermore, the smaller the output voltage, the greater the damping is. The signal loss is about 25.82%. The signal acquisition effect of the PZT square wafer is better than that of circular wafer under the same area of PZT sensor. The research achievements reveal the sensing mechanisms and validate the efficiency of the developed model and effectively simulate and detect direct piezoelectric rule of PZT sensor.

Experimental Research about the Application of ER Elastomer in the Shock Absorber

2013 ◽  
Vol 641-642 ◽  
pp. 371-376 ◽  
Author(s):  
Shi Sha Zhu ◽  
Xue Peng Qian ◽  
Hao He ◽  
Quan Fu Zhang
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Shock Absorber ◽  
Hybrid Control ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Structural Vibration ◽  
Shear Mode ◽  
Response Performance ◽  
Better Than

When the Electrorheological elastomer (ERE) is embedded into intelligence structure system, the structure damping and stiffness of the system can be changed quickly and reversibly under an external electric field. Thus, the application of the Electrorheological elastomer in the active and passive hybrid control of structural vibration has already attracted people's wide attention. In this paper, three types of ER elastomer were prepared based on barium titanate, starch, then the microstructure of ER elastomer was observed and the mechanical properties were analyzed; a shear mode ERE shock absorber was designed, the vibration response performance of which was experimentally evaluated under various excitation frequency with or without the applied field. The experimental results showed that the damping and stiffness of the shock absorber could be modified with a changing external electric field, whose macro-features was that the damping coefficient increased with the increase of the electric field, and the damping effect in the high frequency was better than in the low frequency.

scholarly journals Linear and nonlinear responses to harmonic force in rotating flow

2016 ◽  
Vol 796 ◽  
pp. 306-317 ◽  
Author(s):  
Xing Wei
Keyword(s):  
Resonant Frequency ◽  
Nonlinear Regime ◽  
Rotating Flow ◽  
Force Frequency ◽  
Linear Regime ◽  
Harmonic Force ◽  
Force Amplitude ◽  
Ekman Number ◽  
Suppression Effect ◽  
Linear And Nonlinear

For understanding the dissipation in a rotating flow when resonance occurs, we study the rotating flow driven by the harmonic force in a periodic box. Both the linear and nonlinear regimes are studied. The various parameters such as the force amplitude $a$, the force frequency ${\it\omega}$, the force wavenumber $k$ and the Ekman number $E$ are investigated. In the linear regime, the dissipation at the resonant frequency scales as $E^{-1}k^{-2}$, and it is much stronger than the dissipation at the non-resonant frequencies on large scales and at low Ekman numbers. In the nonlinear regime, at the resonant frequency the effective dissipation (dissipation normalised with the square of the force amplitude) is lower than in the linear regime and it decreases with increasing force amplitude. This nonlinear suppression effect is significant near the resonant frequency but negligible far away from the resonant frequency. Opposite to the linear regime, in the nonlinear regime at the resonant frequency the lower Ekman number leads to lower dissipation because of the stronger nonlinear effect. This work implies that the previous linear calculations overestimated the tidal dissipation, which is important for understanding the tides in stars and giant planets.

scholarly journals Rogowski Coil for Current Measurement in a Cryogenic Environment

2015 ◽  
Vol 15 (2) ◽  
pp. 77-84 ◽  
Author(s):  
Tao Ma ◽  
Shaotao Dai ◽  
Jingye Zhang ◽  
Lianqi Zhao
Keyword(s):  
Output Voltage ◽  
Rogowski Coil ◽  
Measurement Precision ◽  
Current Measurement ◽  
Current Sensor ◽  
Coil Current ◽  
Large Bandwidth ◽  
Current Sharing ◽  
Primary Current ◽  
Better Than

Abstract A Rogowski coil based sensor for current measurement in a cryogenic environment and results of its application for paralleled high temperature superconducting (HTS) coil current sharing are presented. The current sensor consists of a Rogowski coil and an integrator, where the coil output voltage is proportional to the derivative of primary current and the integrator transfers the differentiation to normal state. The Rogowski coil has promising applicability at cryogenic circumstance because its body is made of low temperature materials. The integrator ensures a large bandwidth with feasible magnitude, which is vital for dynamic current measurement during the quench of the HTS coil. The proposed current sensor is used for current sharing measurement of two paralleled Bi2223 HTS coils, and the experimental results show that the measurement precision is better than 0.5%.

Extracting Ionosphere Scintillations Index Based on Single Frequency GPS Software Receiver

2012 ◽  
Vol 190-191 ◽  
pp. 1136-1143
Author(s):  
Zhi Huang ◽  
Hong Yuan ◽  
Qi Yao Zuo
Keyword(s):  
High Speed ◽  
Single Frequency ◽  
Scintillation Index ◽  
Ionospheric Scintillation ◽  
Signal Acquisition ◽  
Gps Receiver ◽  
Signal Loss ◽  
Software Receiver ◽  
Ionospheric Plasma Density ◽  
Gps Signal Acquisition

Scintillations are caused by ionospheric plasma-density irregularities and can lead to signal power fading, loss of lock of the carrier tracking loop in the GPS receiver. The traditional method of monitoring and mitigating scintillation is to transform commercial GPS receiver with modified hardware and embedded software. To better facilitate advance development GPS receiver under different condition, GPS software scintillation receiver is designed in this paper. The hardware scheme of high-speed GPS signal acquisition system is first discussed and implemented with FPGA and DSP architecture. Then, we describe receiver software processing algorithm, particularly the portion involving the scintillation signal acquisition and tracking, ionospheric scintillation index extracting and scintillation monitoring. The performance of software receiver is demonstrated under scintillation conditions. Relevant results show that software-receiver based approach can avoid weak signal loss and extract effectively ionospheric scintillation parameter compared with the traditional extracting method. Software receiver is suitable and reliable for the ionospheric scintillations monitoring, and can provide theoretical foundations and experimental preparations for future scintillation studies implemented with Chinese indigenous BeiDou-Ⅱ navigation and poisoning system.

Testing and Diagnosis of Extra High Voltage Power Cables Using Damped AC Voltages Combined with Distributed Partial Discharge Measurement

2014 ◽  
Vol 1070-1072 ◽  
pp. 1039-1043
Author(s):  
Biao Yan ◽  
Li Zhou ◽  
Jie Chen ◽  
Feng Bo Tao ◽  
Jian Zhang
Keyword(s):  
High Voltage ◽  
Output Voltage ◽  
Partial Discharge ◽  
Assessment Method ◽  
State Assessment ◽  
Signal Acquisition ◽  
Power Cables ◽  
Underground Cable ◽  
Distributed Measurement ◽  
Extra High Voltage

State assessment method of cables with extruded insulation and their accessories, DAC withstand test combined with a diagnostic test (such as PD measurement) has two shortcomings, the output voltage is not high enough for EHV cables, it cannot detect and locate PD effectively when defects are far away from signal acquisition point. This paper focus on DAC voltages up to 250kV and a kind of distributed measurement of PD. Defects existing in arbitrary of tested cable can be accurately measured in theory by installing sensor at intervals along the tested cable. This method has been validated on a long extra high voltage cross-linked polyethylene (XLPE) insulated underground cable circuit and the filed PD test has been completed successfully.

Structure of Mixture Kernel Function and its Application in Soft Measurement about Beating Degree

2011 ◽  
Vol 65 ◽  
pp. 204-207
Author(s):  
Wei Tang ◽  
Yan Zi Zhao
Keyword(s):  
Kernel Function ◽  
Prediction Performance ◽  
Refining Process ◽  
Support Vector ◽  
Wood Industry ◽  
Learning Capacity ◽  
Soft Measurement ◽  
Simulation Results ◽  
Sensor Modeling ◽  
Better Than

Kernel function is dominant in regression process of Support Vector Machine (SVM), it influences the prediction performance of SVM directly. Single local or global kernel function has limitation in generalization or learning capacity. The mixture kernel function with two good capacities had been structured, and it had been used in soft-sensor modeling of refining process. The contrast of simulation results show: the generalization ability of SVM based on mixture kernel function is better than the ones based on the single local or global kernel function, the algorithm had been applied in the refining process of HETAO wood industry factory, and the prediction result meets the requirement of craft production.

Targeted Dropwindsondes in Complex Terrain

2007 ◽  
Vol 24 (8) ◽  
pp. 1489-1494
Author(s):  
Gregory S. Poulos ◽  
Junhong Wang ◽  
Dean K. Lauritsen ◽  
Harold L. Cole
Keyword(s):  
Complex Terrain ◽  
Target Location ◽  
Signal Propagation ◽  
Signal Acquisition ◽  
Target Area ◽  
Horizontal Distance ◽  
Signal Loss ◽  
Geophysical Research ◽  
Rotor Experiment ◽  
Local Relief

Abstract The dropwindsonde (or dropsonde) is a frequently utilized tool in geophysical research and its use over ocean and flat terrain is a reliable and well-established practice. Its use in complex terrain, however, is complicated by signal acquisition challenges that can be directly related to the ground target location, local relief, and line of sight to flight tracks relevant to the observation sought. This note describes a straightforward technique to calculate the theoretical altitude above ground to which a ground-targeted dropsonde will provide data for a given airborne platform. It is found that this height HCq can be calculated from expected airborne platform horizontal velocity Uag, mean dropwindsonde vertical velocity Ws, the relevant barrier maximum HB, and the horizontal distance from the target area to the barrier maximum DB. Here, HCq is found to be weakly dependent on release altitude through Ws. An example from the Terrain-induced Rotor Experiment (T-REX) is used to show that for modern aircraft platforms and dropwindsondes signal loss can occur 1–2 km above ground if mitigation is not pursued. Practical mitigation techniques are described for those complex terrain cases where signal propagation problems would create a significant negative scientific impact.

Large Longitudinal Magnetoelectric Effect in Clamping Structure of TbDyFe Flake, Pb(Zr,Ti)O3 Ring

2013 ◽  
Vol 321-324 ◽  
pp. 273-277
Author(s):  
Jing Liu ◽  
Xiang Yang Li ◽  
Xiao Peng Ye
Keyword(s):  
Magnetoelectric Effect ◽  
Piezoelectric Effect ◽  
Adhesive Layer ◽  
Layered Composites ◽  
Induced Voltage ◽  
Bias Magnetic Field ◽  
Ceramic Ring ◽  
Maximum Value ◽  
Dc Bias ◽  
Better Than

Longitudinal magnetoelectric (ME) effect has been studied in a clamping structure of a magnetostrictive TbDyFe (Terfenol-D), a piezoelectric Pb(Zr,Ti)O3(PZT) ceramic ring. The ME coupling originates from the magnetic-mechanical-electric transform of the magnetostrictive effect in Terfenol-D and the piezoelectric effect in PZT by endpoint bonding, without adhesive layer. In such a clamping structure, Large induced voltage was measured without amplifier, Large longitudinal ME coefficient of 0.12V cm-1Oe-1was obtained at f =1 kHz, which is about 3 times larger than transverse ME coefficient of conventional layered Terfenol-D/PZT composites under the same measuring conditions. The ME coefficient reaches a maximum value at the dc bias magnetic field (Hdc) =280 Oe, which is lower than Hdc =350 Oe in conventional layered composites. The results show that large ME coupling can be achieved without adhesive layer, and longitudinal ME effect can be better than transverse ME effect.

scholarly journals Parametric Characteristics and Bifurcation Analysis of Multi-Degree-of-Freedom Micro Gyroscope with Drive Stiffness Nonlinearity

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 578 ◽  
Author(s):  
Han ◽  
Zhang ◽  
Hao ◽  
Li
Keyword(s):  
Numerical Solutions ◽  
Environmental Changes ◽  
Electrostatic Force ◽  
Excitation Frequency ◽  
Primary Resonance ◽  
Degree Of Freedom ◽  
Dynamic Equations ◽  
Drive Mode ◽  
Force Amplitude ◽  
System Parameters

The dynamic equations of a four-degree-of-freedom micro gyroscope system were developed considering the nonlinearity of driving stiffness, the primary resonance, and the 1:1 internal resonance. Then, the perturbation analysis was carried out using the method of multiple scales. The influence of stiffness nonlinearity and system parameters on micro-gyro dynamic characteristics, output sensitivity, detection bandwidth, and working stability were discussed based on the analytic and numerical solutions of the dynamic equations. Through the singularity theory, the influence of system parameters on bifurcation behavior was analyzed. The results show that the amplitude jump and multi-stable solutions caused by the nonlinear hardening characteristics of the high robust two-degree-of-freedom drive-mode occur outside the detection bandwidth. In addition, the influence on the bandwidth was weak and the sensitivity of the bandwidth area was slightly reduced. Moreover, saturation existed in the response amplitude of the second drive-mode in spite of the primary resonance being completely tuned or detuned. As a result, although the electrostatic force amplitude was out of the unstable region and even took a larger value, the micro gyroscope obtained a larger stable output. Besides, nonlinearity will lead to energy transfer between various modes of multi-degree-of-freedom micro gyroscopes. That means the response amplitudes could change greatly due to the variation of the external environment even the system is under a constant excitation frequency. Therefore, increasing the stiffness coefficient of the micro beam and the electrostatic force amplitude can maintain the robustness of the system to environmental changes and avoid the occurrence of bifurcation.

A Homogenisation Procedure for the Steady State Periodic Forced Response of Laminated Composite Beams at Large Vibration Amplitudes

2012 ◽  
Vol 535-537 ◽  
pp. 1811-1814
Author(s):  
El Bekkaye Merrimi ◽  
Khalid El Bikri ◽  
Rhali Benamar
Keyword(s):  
Steady State ◽  
Excitation Frequency ◽  
Laminated Composite ◽  
Composite Beams ◽  
Forced Response ◽  
Axial Stiffness ◽  
Harmonic Force ◽  
Simple Formulation ◽  
Laminated Composite Beams ◽  
Good Agreement

The purpose of the present paper is to show that the problem of geometrically non linear steady state periodic forced response of symmetrically and asymmetrically laminated composite beams with immovable ends can be reduced to that of isotropic homogeneous beams with effective bending stiffness and axial stiffness parameters. This simple formulation is developed using the governing axial equilibrium equation of the beam in which the axial inertia and damping are ignored. The theoretical model is based on Hamilton’s principle and spectral analysis, to determine the effect of the excitation frequency and level of the applied harmonic force on its dynamic response at large vibration amplitudes, which are found to be in a good agreement with the published results.

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