Piezoelectric cylindrical discs and solid rods: Dependence of the resonance frequencies and effective coupling coefficients on aspect ratio

2016 ◽  
Vol 140 (3) ◽  
pp. 2162-2172 ◽  
Author(s):  
Boris S. Aronov ◽  
Corey L. Bachand
Keyword(s):  
Aspect Ratio ◽  
Coupling Coefficients ◽  
Effective Coupling ◽  
Resonance Frequencies

DIELECTRIC, FERROELECTRIC, PIEZOELECTRIC AND IMPEDANCE STUDY OF LEAD-FREE CERAMIC: SrBi4Ti3.975Zr0.025O15

2012 ◽  
Vol 02 (04) ◽  
pp. 1250023 ◽  
Author(s):  
B. MAMATHA ◽  
P. SARAH
Keyword(s):  
Single Phase ◽  
Electromechanical Coupling ◽  
Xrd Analysis ◽  
Coupling Coefficients ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
Debye Relaxation ◽  
X Ray ◽  
Resonance Frequencies ◽  
Spectroscopy Studies

Polycrystalline SrBi4Ti3.975Zr0.025O15 (SBTZ) was prepared using solid-state reaction technique. SBTZ was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD analysis indicated the formation of a single-phase orthorhombic structure. Particle size was found using SEM. The dielectric, ferroelectric, piezoelectric, modulus and impedance spectroscopy studies on SBTZ were investigated in the frequency range 1 Hz–1 MHz from room temperature (RT) to 600°C. Piezoelectric charge and electromechanical coupling coefficients were calculated from resonance and anti-resonance frequencies. Impedance and modulus plots were used as tools to analyze the sample behavior as a function of frequency. Cole–Cole plots showed a non-Debye relaxation. Conductivity measurements were performed on SBTZ.

Method for determination of effective coupling coefficients in (1 + 1)GTWave fibers

2018 ◽  
Vol 45 ◽  
pp. 363-367
Author(s):  
Mariya G. Slobozhanina ◽  
Anton N. Slobozhanin ◽  
Alexander V. Bochkov ◽  
Dmitry V. Khmelnitsky
Keyword(s):  
Coupling Coefficients ◽  
Effective Coupling

The impact of laterally coupled grating microstructure on effective coupling coefficients

2010 ◽  
Vol 21 (13) ◽  
pp. 134015 ◽  
Author(s):  
R Millett ◽  
K Hinzer ◽  
A Benhsaien ◽  
T J Hall ◽  
H Schriemer
Keyword(s):  
Coupling Coefficients ◽  
Effective Coupling ◽  
The Impact

Properties of Three Phase Magneto-Electro-Thermo-Elastic Composites

2019 ◽  
Vol 969 ◽  
pp. 9-15
Author(s):  
Hardik Patel ◽  
Pavan Kumar Penumakala ◽  
Dhruv Patel
Keyword(s):  
Magnetoelectric Effect ◽  
Epoxy Composite ◽  
Effective Property ◽  
New Product ◽  
Longitudinal Direction ◽  
Coupling Coefficients ◽  
Effective Coupling ◽  
Property Variation ◽  
Three Phase ◽  
Elastic Composites

Three phase composites that consists of piezoelectric and piezomagnetic fibers embedded inan elastic matrix phase exhibits new product properties such as magnetoelectric effect, pyroelectric andpyromagnetic effect, which are absent in individual phases. In this work, simple analytical expressionsare developed based on strength of materials approach to find these effective coupling coefficients. In amicro scale rectangular representative volume element (RVE) of a layered type three phase composite,series connectivity is assumed between fiber and matrix layers along transverse direction and parallelconnectivity is assumed along longitudinal direction. The analytical model is validated with otherhomogenisation methods and effective property variation of BaTiO3-CoFe2O4-Epoxy composite andLiNbO3-CoFe2O4- Epoxy composite are discussed.

Magnetomechanical Properties of Circumferentially Field-Annealed Metglas® 2605SC Cylinders

1994 ◽  
Vol 360 ◽  
Author(s):  
J. B. Restorff ◽  
M. Wun-Fogle ◽  
A. E. Clark ◽  
Thu-Van T. Luu
Keyword(s):  
Coupling Coefficient ◽  
Longitudinal Mode ◽  
Bias Field ◽  
Coupling Coefficients ◽  
Effective Coupling ◽  
Impedance Measurements ◽  
Annealing Temperatures ◽  
Large Numbers ◽  
Demagnetizing Factor ◽  
A Current

AbstractWe have measured the magnetomechanical coupling coefficient of Metglas®2605SC (Fe81B13.5C2) ribbons that were annealed into 1.27 and 0.8 cm diameter cylinders. Lengths ranged from 0.6 to 5 cm. A novel furnace was constructed in which a cylindrical magnetic field was supplied by a current carrying copper rod. During the annealing, a 300 A current created a circumferential field of more than 6400 A/m. Annealing temperatures ranged from 380 to 420 ºC. Large shifts in both the optimum bias field and the coupling coefficient as a function of length and diameter were found due to demagnetizing effects. Impedance vs. frequency measurements show large numbers of modes, some of which are field dependent. Effective coupling coefficientsof the lowest order longitudinal mode were calculated from impedance measurements by using k2 = 1-f2r/f2a, where fr, and fa. are the resonant and antiresonant frequencies respectively. Coupling coefficients for 5 cm long cylinders were as high as 0.58. When the demagnetizing factor is taken into account, we find material coupling coefficients as high as 0.89.

A comparison of Pd and Au electrodes-based LiNbO3 surface acoustic wave devices

2016 ◽  
Vol 30 (32n33) ◽  
pp. 1650349 ◽  
Author(s):  
Bo Liu ◽  
Mohammad Ali Mohammad ◽  
Dan-Yang Wang ◽  
Xiang-Guang Tian ◽  
Lu-Qi Tao ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Resonance Frequency ◽  
Quality Factor ◽  
Surface Acoustic Wave ◽  
Electromechanical Coupling ◽  
Coupling Coefficients ◽  
Third Order ◽  
Au Electrode ◽  
Saw Devices ◽  
Resonance Frequencies

We report the comparison of electrode metals for LiNbO3 surface acoustic wave (SAW) devices. Palladium (Pd) was systematically studied as a SAW electrode metal for the first time, compared with gold (Au). Simulations were first conducted to gain an understanding of the differences of the materials and the metallization ratio. Two sets of identical SAW devices were then fabricated using Au and Pd as electrodes with different electrode widths and same SAW period. The insertion losses, types of resonance mode, the resonance frequencies, peak amplitudes, quality factors and trends with different metallization ratios were systematically compared and analyzed. We found that Pd electrode devices only exhibit the parallel resonance frequency and have higher resonance frequency for both the first-order and third-order harmonics. Au electrode devices tend to have a smooth response and a quality factor two times higher than Pd. Both Pd and Au electrode devices have nearly identical electromechanical coupling coefficients, and the quality factor and third-order harmonics both improve with increasing metallization ratio.

scholarly journals Parametric Study of Bolt Clamping Effect on Resonance Characteristics of Langevin Transducers with Lumped Circuit Models

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1952 ◽  
Author(s):  
Jinhyuk Kim ◽  
Jungwoo Lee
Keyword(s):  
Parametric Study ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Coefficient ◽  
Model Parameters ◽  
Test Results ◽  
Coupling Coefficients ◽  
Resonance Modes ◽  
At Resonance ◽  
Resonance Frequencies ◽  
Effective Electromechanical Coupling Coefficient

We recently proposed a numerical model using equivalent circuit models to analyze the resonance characteristics of Langevin transducers and design them in a systematic manner. However, no pre-load torque biased by a metal bolt was considered in the model. Here, a parametric study is, therefore, carried out to reveal how model parameters are adapted to incorporate the pre-compression effect into our existing model. Analytical results are compared with corresponding experimental data, particularly regarding the input electrical impedance and effective electromechanical coupling coefficient for the transducer at resonance modes. The frequency response of input impedance is presented as a function of torque, both theoretically and experimentally. For 10.0 N·m bias, for instance, both resonance and anti-resonance frequencies are calculated as 38.64 kHz and 39.78 kHz, while these are measured as 38.62 kHz and 39.77 kHz by the impedance analyzer. The impedance difference between these cases is 14 Ω at resonance and 9 kΩ at anti-resonance, while the coupling coefficients in both cases become 0.238 and 0.239, respectively. Hence, these test results are closely matched with their theoretical values. Consequently, this study provides a quantitative guideline that specifies the pre-loading condition of bolt clamps with proper parameter settings to predict the intended resonance characteristics of Langevin transducers.

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