scholarly journals Design and Fabrication of a Wideband Cymbal Transducer for Underwater Sensor Networks

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4659 ◽  
Author(s):  
Hayeong Shim ◽  
Yongrae Roh
Keyword(s):  
Power Efficiency ◽  
Structural Parameters ◽  
Mechanical Quality Factor ◽  
Voltage Response ◽  
Underwater Sensor Networks ◽  
The Finite Element Method ◽  
Network Systems ◽  
Power Requirement ◽  
Cymbal Transducer ◽  
Mechanical Quality

Cymbal transducers are characterized by a high mechanical quality factor and low power efficiency. The research conducted so far on cymbal transducers has focused on improving the power efficiency and structural stability, but modern underwater sensor network systems need transducers to have a wide frequency bandwidth as well. In this study, a wideband cymbal transducer was designed to fill that need. First, the effect of various structural parameters on the performance of the cymbal transducer was analyzed with emphasis on the bandwidth using the finite element method. Based on the analysis results, the structure of the cymbal transducer was optimized to have the widest possible bandwidth while maintaining its transmitting voltage response (TVR) level over a typical power requirement as well. The validity of the design was verified by fabricating a prototype of the optimized cymbal transducer and comparing its measured performance with the design.

Optimizing Mechanical Quality Factor of Cymbal Transducer

2006 ◽  
Vol 331 (1) ◽  
pp. 65-71
Author(s):  
A. Dogan ◽  
A. E. Uzgur ◽  
Z. O. Yazici ◽  
Anne-Christine Hladky-Hennion
Keyword(s):  
Quality Factor ◽  
Mechanical Quality Factor ◽  
Cymbal Transducer ◽  
Mechanical Quality

scholarly journals Design of an Acoustic Bender Transducer for Active Sonobuoys

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1691 ◽  
Author(s):  
Pyo ◽  
Shim ◽  
Roh
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Performance ◽  
Structural Parameters ◽  
Underwater Vehicles ◽  
Acoustic Properties ◽  
Voltage Response ◽  
Sound Waves ◽  
The Finite Element Method ◽  
High Detection

Recent underwater vehicles can operate with a much lower level of noise, which increases the need for an active sonobuoy with a high detection performance. These active sonobuoys mainly use bender transducers as a projector that emits sound waves. In this study, we designed a high-performance bender transducer and verified the validity of the design through experiments. For this purpose, first we analyzed the variation of the peak transmitting voltage response (TVR) level and peak TVR frequency of the bender transducer, in relation to its structural parameters. The performance of the bender transducer was analyzed using the finite element method. Then we derived the optimal structure of the bender transducer to achieve the highest TVR. Based on the design, a prototype of the bender transducer was fabricated and its acoustic properties were measured to confirm the validity of the design.

scholarly journals Research and Fabrication of Broadband Ring Flextensional Underwater Transducer

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1548
Author(s):  
Jiuling Hu ◽  
Lianjin Hong ◽  
Lili Yin ◽  
Yu Lan ◽  
Hao Sun ◽  
...  
Keyword(s):  
High Speed ◽  
Structural Parameters ◽  
Low Frequency ◽  
Flexural Vibration ◽  
Underwater Acoustic Communication ◽  
Voltage Response ◽  
Water Tank ◽  
Spherical Cap ◽  
Finite Element Software ◽  
Underwater Transducer

At present, high-speed underwater acoustic communication requires underwater transducers with the characteristics of low frequency and broadband. The low-frequency transducers also are expected to be low-frequency directional for realization of point-to-point communication. In order to achieve the above targets, this paper proposes a new type of flextensional transducer which is constructed of double mosaic piezoelectric ceramic rings and spherical cap metal shells. The transducer realizes broadband transmission by means of the coupling between radial vibration of the piezoelectric rings and high-order flexural vibration of the spherical cap metal shells. The low-frequency directional transmission of the transducer is realized by using excitation signals with different amplitude and phase on two mosaic piezoelectric rings. The relationship between transmitting voltage response (TVR), resonance frequency and structural parameters of the transducer is analyzed by finite element software COMSOL. The broadband performance of the transducer is also optimized. On this basis, the low-frequency directivity of the transducer is further analyzed and the ratio of the excitation signals of the two piezoelectric rings is obtained. Finally, a prototype of the broadband ring flextensional underwater transducer is fabricated according to the results of simulation. The electroacoustic performance of the transducer is tested in an anechoic water tank. Experimental results show that the maximum TVR of the transducer is 147.2 dB and the operation bandwidth is 1.5–4 kHz, which means that the transducer has good low-frequency, broadband transmission capability. Meanwhile, cardioid directivity is obtained at 1.4 kHz and low-frequency directivity is realized.

A Study of the Anchor Effect Based on Structural Parameters of Flexible Pressurized Anchor and Pressure from Surrounding Rock

2011 ◽  
Vol 71-78 ◽  
pp. 4634-4637
Author(s):  
Tian Lin Cui ◽  
Jing Kun Pi ◽  
Yong Hui Liu ◽  
Zhen Hua He
Keyword(s):  
Structural Parameters ◽  
Structural Features ◽  
Surrounding Rock ◽  
Design Parameters ◽  
Optimized Design ◽  
Anchor Effect ◽  
The Finite Element Method ◽  
Anchor System ◽  
New Type ◽  
Stress Relation

In order to optimize the design of flexible pressurized anchor, this paper gives a further analysis on structural features of the new type of flexible pressurized anchor and carries out a contact analysis on anchor system by using the finite element method. It calculates as well as researches the contact stress relation of interactional anchor rod and surrounding rock under the circumstance of anchoring, obtaining the law of all major design parameters of anchor rod structure and pressure from surrounding rock influencing the anchoring performance and arriving at the conclusion that the anchor rod is adapted to various conditions of surrounding rock. They not only serve as important references for optimized design and application of anchor rod, but also provide a basis for the experiment of new type of anchor rod.

scholarly journals Mechanical Quality Factor of Pb(ZrxTi 1−x) 1−y (Mg1/3Nb2/3)yO3 Solid Solution Prepared by Wet-Dry Combination Method

1999 ◽  
Vol 67 (10) ◽  
pp. 985-987
Author(s):  
Yoshiyuki ABE ◽  
Taisyu YANAGISAWA ◽  
Kazuyuki KAKEGAWA ◽  
Yoshinori SASAKI
Keyword(s):  
Solid Solution ◽  
Quality Factor ◽  
Mechanical Quality Factor ◽  
Combination Method ◽  
Mechanical Quality

Piezoelectric Properties of PZT-5 Fiber/Epoxy Resin 1-3 Composites

2011 ◽  
Vol 239-242 ◽  
pp. 486-489
Author(s):  
Ling Fang Xu ◽  
Wen Chen ◽  
Jing Zhou ◽  
Chang Ping Yang
Keyword(s):  
Epoxy Resin ◽  
Coupling Coefficient ◽  
Piezoelectric Properties ◽  
Volume Fraction ◽  
Mechanical Quality Factor ◽  
Casting Method ◽  
Anisotropic Property ◽  
Niobium Doped ◽  
Mechanical Quality ◽  
Method Effects

Niobium doped Pb(Zr,Ti)O3fiber/epoxy resin 1-3 composites with different ceramic volume fraction of 10-85% were fabricated by filling-casting method. Effects of ceramic volume fraction on electric properties were investigated. For a typical 30% ceramic content composite, the thickness coupling coefficientkt, mechanical quality factorQm, acoustic impedanceZmand anisotropic propertykt/kpwere 0.67, 0.55, 11.03 MRayl and 2.23, respectively.

A Microcontroller Approach to Measuring Transmissibility of MEMS Devices

2015 ◽  
Vol 2015 (DPC) ◽  
pp. 001564-001593
Author(s):  
Chong Li ◽  
Yixuan Wu ◽  
Haoyue Yang ◽  
Luke L. Jenkins ◽  
Robert N. Dean ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Quality Factor ◽  
Real Time ◽  
High Speed ◽  
Mechanical Quality Factor ◽  
Quantization Noise ◽  
Mems Devices ◽  
Input And Output ◽  
Mechanical Quality ◽  
Mems Device

The transmissibility reveals two very useful characteristics of a micro-electro-mechanical systems (MEMS) device, the resonant frequency and the mechanical quality factor. Real time knowledge on these two important factors can enhance application performance or avoid potential problems from environmental disturbances due to fabrication tolerances and the resulting operational differences in otherwise identical devices. Expensive laboratory equipment is typically used to measure the transmissibility. However, these test systems are not readily adaptable to field use. Therefore, it is important to be able to measure the transmissibility using a real time technique with a simplified test setup. This study proposes a technique that can compute the transmissibility in real time using a low cost microcontroller. This technique utilizes two laser vibrometers to detect the input and output motions of the proof mass in a MEMS device, which are fed to high speed 500 KHz analog to digital converters (ADC) in the microcontroller. A filtering step is performed to decrease noise. After the sampling and pre-filtering, a Fast Fourier Transform (FFT) is performed to convert the time-domain signals to frequency domain signals. The amplitude of the output signal at each frequency is divided by the amplitude of the corresponding input signal at each frequency to obtain the transmissibility. To overcome the difficulties resulting from measurement and quantization noise, a recursive calculating algorithm and a de-quantization filter are introduced. The recursive calculating process guarantees that the system updates the results continually, which results in a transmissibility plot covering the entire bandwidth. The de-quantization filter considers the validity of the data and performs the transmissibility division step accordingly. A cantilevered structure was chosen as the device-under-test to verify and evaluate this technique. The cantilevered device was attached to an electromechanical shaker system for vibratory stimulation. Two laser vibrometers were used to detect the input and output motion and this data was fed into a microcontroller. The microcontroller was STM32F407, which is 32-bit and 168 MHz controller. The tests demonstrated that this technique can measure the transmissibility and therefore the resonant frequency and mechanical quality factor accurately compared to a professional signal analyzer.

scholarly journals Modelling a Cracked Beam Structure Using the Finite Element Displacement Method

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Hui Long ◽  
Yilun Liu ◽  
Changzheng Huang ◽  
Weihui Wu ◽  
Zhaojun Li
Keyword(s):  
Finite Element ◽  
Dynamic Model ◽  
Structural Parameters ◽  
Element Model ◽  
Beam Element ◽  
The Finite Element Method ◽  
Displacement Method ◽  
Beam Structure ◽  
Cracked Beam ◽  
Local Flexibility

A new model is presented for studying the effects of crack parameters on the dynamics of a cracked beam structure. The model is established by the finite element displacement method. In particular, the stiffness matrix of the cracked beam element is firstly derived by the displacement method, which does not need the flexibility matrix inversion calculation compared with the previous local flexibility approaches based on the force method. Starting with a finite element model of cracked beam element, the equation of strain energy of a cracked beam element is formed by the displacement method combined with the linear fracture mechanics. Then, based on the finite element method, the dynamic model of the cracked beam structure is obtained. The results show that the dynamic model discovers the internal relation between the dynamic characteristics of cracked beam structure and structural parameters, material parameters, and crack parameters. Finally, an example is presented to validate the proposed dynamic model.

Influence MnO2 on the Properties of (LixNayK1-x-y)NbO3 Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 199-202
Author(s):  
Qiang Chen ◽  
De Jun Lan ◽  
Yi Chen ◽  
Du Min Lin ◽  
Xi Yue ◽  
...  
Keyword(s):  
Composition Range ◽  
Sintering Temperature ◽  
Mechanical Quality Factor ◽  
Piezoelectric Constant ◽  
Potassium Niobate ◽  
Sodium Potassium ◽  
Sodium Potassium Niobate ◽  
State Process ◽  
Mechanical Quality ◽  
Curie Temperature Tc

Lead-free piezoelectric ceramics lithium sodium potassium niobate (LixNayK1-x-y)NbO3 (LNKN100x/100y) have been synthesized by a conventional solid state process. The effects of MnO2 addition on the properties of (LixNayK1-x-y)NbO3(x=0.06, y=0.5)(LNKN6/50) ceramics were investigated. It was found that a morphotropic phase boundary (MPB) between orthorhombic and tetragonal phases is in the composition range 0.05<x<0.07. The piezoelectric constant d33 and the planar electromechanical coefficient kp of LNKN6/50 ceramics reach 222pC/N and 39%, respectively. As the amount of MnO2- doped increases, dielectric constant, piezoelectric constant and Curie temperature Tc of LNKN:Mn ceramics decreased, while mechanical quality factor Qm of LNKN6/50:Mn increased prominently compared to pure LNKN6/50 ceramics. The addition of MnO2 can also decrease the sintering temperature effectively of LNKN6/50 ceramics.

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