Research on Dynamics Measurement of Piezoelectric Sensor Based on PVDF Films

2014 ◽  
Vol 496-500 ◽  
pp. 1473-1476
Author(s):  
Qi Zhang ◽  
Ying Jun Li ◽  
Gui Cong Wang ◽  
Ru Jian Ma ◽  
Xiu Yun Zhao
Keyword(s):  
Mathematical Models ◽  
Natural Frequency ◽  
Piezoelectric Effect ◽  
Theoretical Calculations ◽  
Piezoelectric Sensor ◽  
Dynamic Measurements ◽  
Support Structure ◽  
Calculating Method ◽  
New Type ◽  
Lower Cover

A new type of upper and lower cover support structure piezoelectric sensor based on PVDF films is designed in terms of piezoelectric effect. Mechanics and mathematical models are established according to the structure of the sensor. The natural frequency of the sensor is derived finally. The natural frequency of the sensor is verified to meet the requirements of dynamic measurements by using theoretical calculations and simulations. The effectiveness of the calculating method is indicated.

Theoretical and experimental research on slip and uplift of the timber-concrete composite beam

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 7079-7099
Author(s):  
Jianying Chen ◽  
Guojing He ◽  
Xiaodong (Alice) Wang ◽  
Jiejun Wang ◽  
Jin Yi ◽  
...  
Keyword(s):  
Differential Equations ◽  
Deformation Theory ◽  
Concrete Slab ◽  
Theoretical Calculations ◽  
Structural Element ◽  
Structural Efficiency ◽  
Theoretical Investigations ◽  
New Type ◽  
Interlayer Slip ◽  
Good Agreement

Timber-concrete composite beams are a new type of structural element that is environmentally friendly. The structural efficiency of this kind of beam highly depends on the stiffness of the interlayer connection. The structural efficiency of the composite was evaluated by experimental and theoretical investigations performed on the relative horizontal slip and vertical uplift along the interlayer between composite’s timber and concrete slab. Differential equations were established based on a theoretical analysis of combination effects of interlayer slip and vertical uplift, by using deformation theory of elastics. Subsequently, the differential equations were solved and the magnitude of uplift force at the interlayer was obtained. It was concluded that the theoretical calculations were in good agreement with the results of experimentation.

Study on the working state of the five hundred-meter aperture spherical telescope using step-wise assignment method

2014 ◽  
Vol 229 (2) ◽  
pp. 316-324 ◽  
Author(s):  
Yu Liu ◽  
Feng Gao
Keyword(s):  
Nonlinear Equations ◽  
Analytical Solutions ◽  
Driving Mechanism ◽  
Initial Value ◽  
Unknown Parameters ◽  
Support Structure ◽  
Assignment Method ◽  
New Type ◽  
Set Up ◽  
The Mathematical Model

The working state of the five hundred-meter aperture spherical telescope (FAST) is solved using the step-wise assignment method. In this paper, the mathematical model of the cable-net support structure of the FAST is set up by the catenary equation. There are a large number of nonlinear equations and unknown parameters of the model. The nonlinear equations are solved by using the step-wise assignment method. The method is using the analytical solutions of the cable-net equations of one working state as the initial value for the next working state, from which the analytical solutions of the nonlinear equations of the cable-net for each working state of the FAST and the tension and length of each driving cable can be obtained. The suggested algorithm is quite practically well suited to study the working state of the cable-net structures of the FAST. Also, the working state analysis result of the cable-net support structure of a reduced model of the cable-net structure reflector for the FAST is given to verify the reliability of the method. In order to show the validity of the method, comparisons with another algorithm to set the initial value are presented. This method has an important guiding significance to the further study on the control of the new type of flexible cable driving mechanism, especially the FAST.

Paper 6: Electronic Instrumentation Techniques in the Development of Pistons and Rings

1965 ◽  
Vol 180 (7) ◽  
pp. 54-69 ◽  
Author(s):  
M. H. Westbrook ◽  
R. Munro
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Extreme Conditions ◽  
Dynamic Measurements ◽  
Inductive Transducer ◽  
New Type ◽  
Electronic Instrumentation ◽  
Mechanical Linkage ◽  
Contact Displacement ◽  
Engine Development

Both general and particular aspects of the application of electronic instrumentation in internal combustion engine development are discussed, and the work which has been carried out in the authors' establishment on instrumentation for dynamic measurements on the piston assembly is described, in particular, measurements of engine noise and vibration, and of displacement and temperature during operation, using telemetry systems, and making use of both radio and mechanical linkage techniques. The development of a new type of sub-miniature inductive transducer for non-contact displacement measurement under the extreme conditions inside a working piston is described, and the reasons making its development necessary discussed. Results obtained from a working engine showing piston movements as measured by several inductive transducers and transmitted over the linkage system are shown and compared to block vibration recordings made simultaneously; an initial interpretation of the very recent results is made. Finally, electronic methods developed for the static measurement of piston and ring properties are described and the results obtained discussed.

The Research of Calculation Method on Vertical Natural Frequency of the New Full-Prefabricated Floor

2016 ◽  
Vol 846 ◽  
pp. 506-511
Author(s):  
Chong Fang Sun ◽  
Shu Ting Liang ◽  
Xiao Jun Zhu
Keyword(s):  
Numerical Simulation ◽  
Natural Frequency ◽  
Calculation Method ◽  
Variable Stiffness ◽  
Series Method ◽  
Numerical Simulation Result ◽  
Stiffness Method ◽  
Calculation Results ◽  
New Type ◽  
Test Result

New-type floor is composed of three kinds of slabs joined together through fittings. It is a kind of anisotropic two-way slab. In order to study the calculation method of natural frequency, series method, variable thickness method and variable stiffness method are adopted to calculate the natural frequency. The calculation results of three methods are compared with test result and numerical simulation result. The conclusion is that the calculation result of the variable stiffness method is the closest to the real natural frequency of new-type floor.

Metal-Core Piezoelectric Fibers for the Detection of Lamb Waves

2010 ◽  
Author(s):  
Jian Liu ◽  
Jinhao Qiu ◽  
Weijie Chang ◽  
Hongli Ji ◽  
Kongjun Zhu
Keyword(s):  
Lamb Wave ◽  
Piezoelectric Effect ◽  
Lamb Waves ◽  
Guided Wave ◽  
Voltage Response ◽  
Metal Core ◽  
Direct Piezoelectric Effect ◽  
New Type ◽  
Sensor Voltage ◽  
Piezoelectric Fiber

Metal-core piezoelectric fiber (MPF) is a new type of piezoelectric ceramic device with small size, and has great potential to be used as structurally integrated transducers for guided-wave (GW) structural health monitoring. This paper focuses on the use of MPF as ultrasonic Lamb wave receivers. First, the MPF sensor voltage response is derived by coupling the direct piezoelectric effect to the wave strain field excited by circular crested actuator. The obtained theoretical result is validated on an aluminum plate. Furthermore, the experiment that compares the MPF response to Lamb wave with the PZT response is performed. The results show that MPF sensors can be used to sense Lamb waves clearly. In the end, the directivity of MPF response to Lamb waves was investigated, and another experiment is performed to examine the directivity of MPF response to Lamb waves. The result shows that MPF has high directivity, which can be exploited to triangulate the location of an ultrasound source without prior knowledge of the wave velocity in the medium.

Influencing Factors Analysis on Comfort of New-Type Precast Assembly Diaphragm

2014 ◽  
Vol 578-579 ◽  
pp. 711-716
Author(s):  
Chong Fang Sun ◽  
Shu Ting Liang ◽  
Xiao Jun Zhu
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Influencing Factors ◽  
Evaluation Criteria ◽  
Simulation Method ◽  
Factors Analysis ◽  
Comfort Evaluation ◽  
Element Simulation ◽  
New Type ◽  
Design Proposal

The paper selected natural frequency and peak acceleration as comfort evaluation criteria. The author tested the new floor comfort under the human-induced loads. The author analyzed new floor comfort by selecting the worst possible scenarioes. The result indicates that the new floor satisfies the comfort requirement. The comparison of test value, theoretical value and finite element value of natural frequency proved that the finite element simulation was reasonable. The author analyzed comfort influencing factors of 7m×7m floor with the same simulation method and proposed a design proposal.

scholarly journals Pressure-induced superconductivity in a three-dimensional topological material ZrTe5

2016 ◽  
Vol 113 (11) ◽  
pp. 2904-2909 ◽  
Author(s):  
Yonghui Zhou ◽  
Juefei Wu ◽  
Wei Ning ◽  
Nana Li ◽  
Yongping Du ◽  
...  
Keyword(s):  
High Pressure ◽  
Theoretical Calculations ◽  
Structural Phase ◽  
Applied Pressure ◽  
Extreme Environments ◽  
Three Dimensional ◽  
Maximum Pressure ◽  
Superconducting Transition ◽  
Topological Materials ◽  
New Type

As a new type of topological materials, ZrTe5 shows many exotic properties under extreme conditions. Using resistance and ac magnetic susceptibility measurements under high pressure, while the resistance anomaly near 128 K is completely suppressed at 6.2 GPa, a fully superconducting transition emerges. The superconducting transition temperature Tc increases with applied pressure, and reaches a maximum of 4.0 K at 14.6 GPa, followed by a slight drop but remaining almost constant value up to 68.5 GPa. At pressures above 21.2 GPa, a second superconducting phase with the maximum Tc of about 6.0 K appears and coexists with the original one to the maximum pressure studied in this work. In situ high-pressure synchrotron X-ray diffraction and Raman spectroscopy combined with theoretical calculations indicate the observed two-stage superconducting behavior is correlated to the structural phase transition from ambient Cmcm phase to high-pressure C2/m phase around 6 GPa, and to a mixture of two high-pressure phases of C2/m and P-1 above 20 GPa. The combination of structure, transport measurement, and theoretical calculations enable a complete understanding of the emerging exotic properties in 3D topological materials under extreme environments.

Research on Design and Nonlinear of Piezoelectric Pressure Sensor

2014 ◽  
Vol 530-531 ◽  
pp. 50-53
Author(s):  
Guo Min Lin ◽  
Fei Zhou ◽  
Chun Feng Li
Keyword(s):  
Key Words ◽  
Equivalent Circuit ◽  
Natural Frequency ◽  
Pressure Sensor ◽  
Influence Factors ◽  
Piezoelectric Sensor ◽  
Effective Area ◽  
Tightening Force ◽  
Piezoelectric Wafer ◽  
Piezoelectric Pressure Sensor

Measuring circuit and equivalent circuit of piezoelectric sensor and its parameters of voltage, capacitance and charge are analyzed. The intensity, the sensitivity and natural frequency of pressure sensor are designed. The influence factors and compensation method of pressure sensor nonlinear such as effective area of diaphragm, pre-tightening force, and temperature are analyzed. Key words: Sensor; Piezoelectric wafer; Measure circuit; Equivalent circuit; Nonlinear

scholarly journals Твердотельный изгибно-вибрационный датчик низкочастотного магнитного поля на основе пьезоэлектрического эффекта

2019 ◽  
Vol 89 (2) ◽  
pp. 206
Author(s):  
А.Е. Панич ◽  
Г.С. Радченко ◽  
А.В. Скрылев ◽  
А.А. Панич ◽  
А.Ю. Малыхин
Keyword(s):  
Magnetic Field ◽  
Theoretical Calculations ◽  
Low Frequency ◽  
Piezoelectric Sensor ◽  
Piezoelectric Response ◽  
Small Signal ◽  
Hybrid Magnet ◽  
Effective Response ◽  
Magnetic Action ◽  
Electrophysical Parameters

AbstractOptimal geometrical and electrophysical parameters are calculated theoretically; the effective response of a solid-state hybrid “magnet–carbon—piezoelectric” sensor is studied experimentally. Experiments are performed under the action of an external magnetic field of low-frequency flexural resonances (from 1 to 230 Hz). Theoretical calculations have formed the basis for designing an experimental prototype of the instrument. The frequency dependence of the direct piezoelectric response to the applied small-signal varying magnetic action is constructed.

scholarly journals Dynamic absorber for ropeway gondola using Coriolis force

2008 ◽  
Vol 30 (4) ◽  
Author(s):  
Hiroshi Matsuhisa ◽  
Masashi Yasuda
Keyword(s):  
Natural Frequency ◽  
Coriolis Force ◽  
Large Amplitude ◽  
Theoretical Predictions ◽  
New Type ◽  
Small Model ◽  
Dynamic Absorber

Wind-induced swinging of ropeway gondola can be reduced using dynamic absorbers. To maximize the performance of conventional dynamic absorbers, their location should be as high as possible. However, absorbers can not be installed at high positions due to interference issues with structures such as towers and stations. To address this problem, a new type of dynamic absorber that moves vertically is proposed. This absorber is composed of a mass supported by a spring. The mass moves in the radius direction (up and down) and it induces Coriolis force in the circumference direction to prevent the swing of gondola. If the natural frequency of the absorber is tuned to twice that of the gondola, the absorber moves spontaneously with a large amplitude due the resonance. This absorber is more effective when it is located at lower positions. The experiment with a small model and an actual gondola for 10 passengers were carried out and the results agreed well with the theoretical predictions.

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