scholarly journals Experimental validation of piezoelectric shunt tuning with residual mode correction: Damping of plate-like structures

2020 ◽  
Vol 31 (9) ◽  
pp. 1220-1239
Author(s):  
Johan Frederik Toftekær ◽  
Jan Høgsberg
Keyword(s):  
Electromechanical Coupling ◽  
Copper Wire ◽  
Short Circuit ◽  
Single Mode ◽  
Magnetic Core ◽  
Open Circuit ◽  
Electromechanical Coupling Coefficient ◽  
Tuning Method ◽  
Multi Mode ◽  
Free Beam

The effective vibration mitigation properties of piezoceramic patches with inductive-resistive shunts are investigated experimentally. A shunt tuning method is proposed, in which a consistent correction for the influence from residual vibration modes is included by an effective modal capacitance, evaluated from measured charge and voltage amplitudes in short- and open-circuit conditions, respectively. The robustness of the proposed method is verified experimentally for both a free beam and a free plate structure with four shunted piezoceramic patch pairs. A stable and fully passive inductor is produced by winding a copper wire around a magnetic core, which requires precise inductance tuning to determine the final number of turns. It is demonstrated that the effective modal capacitance interpolates consistently between the blocked and static capacitances, commonly used for single-mode tuning of piezoelectric inductive-resistive shunts. By imposing pseudo-random vibrations, the piezoelectric current and voltage signals are measured and evaluated by their frequency response functions. Spectrum peak values determine the apparent short-circuit charge to open-circuit voltage ratio for each shunt, which directly determines the shunt components by explicit tuning formulas. Good correlation between numerical and experimental results are obtained for the free beam, while for the free plate experiment effective multi-mode shunt tuning is obtained by a modified effective electromechanical coupling coefficient.

Thermal Conductivities of PZT Piezoelectric Ceramics under Different Electrical Boundary Conditions

2020 ◽  
Vol 3 (1) ◽  
pp. 10
Author(s):  
Husain N.  Shekhan ◽  
Erkan A.  Gurdal ◽  
Lalitha Ganapatibhotla ◽  
Janna K.  Maranas ◽  
Ron Staut ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Boundary Conditions ◽  
Lead Zirconate Titanate ◽  
Electromechanical Coupling ◽  
Short Circuit ◽  
Coupling Factor ◽  
Open Circuit ◽  
Electrical Boundary Conditions ◽  
Poling Direction

<p>Physical properties of polycrystalline lead-zirconate-titanate (PZT) changes according to electrical boundary conditions and poling. This paper reports the thermal properties of poled and unpoled PZT's in the poling direction for open circuit and short circuit conditions. The authors found that the short-circuit condition exhibited the largest thermal conductivity than the open-circuit condition. In the relationship between these two thermal properties, the authors propose the "electrothermal" coupling factor k<sup>κ</sup><sub>33</sub>, which is similar to the electromechanical coupling factor k<sub>33</sub> relating the elastic compliances under short- and open-circuit conditions. On the other hand, the thermal conductivity of the unpoled specimen exhibits the lowest thermal conductivity, in comparison with the poled specimens, which suggests the importance of phonon mode scattering on the thermal conductivity with respect to elastic compliance.</p>

scholarly journals Optimal piezoelectric resistive–inductive shunt damping of plates with residual mode correction

2018 ◽  
Vol 29 (16) ◽  
pp. 3346-3370 ◽  
Author(s):  
Johan F Toftekær ◽  
Ayech Benjeddou ◽  
Jan Høgsberg ◽  
Steen Krenk
Keyword(s):  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Vibration Suppression ◽  
Equations Of Motion ◽  
Open Circuit ◽  
Electromechanical Coupling Coefficient ◽  
Inertia Effects ◽  
Resonant Modes ◽  
Calibration Methods ◽  
Shunt Damping

This work concerns vibration suppression of plates and plate-like structures by resonant piezoelectric damping, introduced by resistive–inductive shunts. The performance of this type of shunt damping relies on the precise calibration of the shunt frequency, where an important aspect is the ability to account for the energy spill-over from the non-resonant modes, not taken into account by most available calibration methods. A newly proposed calibration procedure includes this residual mode contribution by a quasi-dynamic modal correction, taking both flexibility and inertia effects of the non-resonant modes into account. In this work, this procedure is implemented in a finite element model combining Kirchhoff plate bending kinematics for the host structure and a plane stress assumption for a pair of bonded piezoceramic patches. The established model is verified by comparison with shunt calibrations from benchmark examples in the literature. As demonstrated by frequency response plots and the obtained damping ratios, the resistive–inductive shunt tuning is influenced by the effect of the non-resonant modes and omission may yield a significant detuning of the shunt circuit. Finally, an alternative method for precise evaluation of the effective (or generalized) electromechanical coupling coefficient is derived from the modal electromechanical equations of motion. This results in a new shunt tuning method, based on the effective electromechanical coupling coefficient obtained by the short- and open-circuit frequencies of the coupled piezo-plate structure.

scholarly journals A New Electrical Circuit With Negative Capacitances to Enhance Resistive Shunt Damping

2015 ◽  
Author(s):  
Marta Berardengo ◽  
Stefano Manzoni ◽  
Olivier Thomas ◽  
Christophe Giraud-Audine
Keyword(s):  
Electromechanical Coupling ◽  
Short Circuit ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Open Circuit ◽  
Electrical Circuit ◽  
Structural Vibration ◽  
Electrical Network ◽  
Negative Capacitance ◽  
Shunt Damping

This article proposes a new layout of electrical network based on two negative capacitance circuits, aimed at increasing the performances of a traditional resistive piezoelectric shunt for structural vibration reduction. It is equivalent to artificially increase the modal electromechanical coupling factor of the electromechanical structure by both decreasing the short-circuit natural frequencies and increasing the open-circuit ones. This leads to higher values of the modal electromechanical coupling factor with respect to simple negative capacitance configurations, when the same margin from stability is considered. This technique is shown to be powerful in enhancing the control performance when associated to a simple resistive shunt, usually avoided because of its poor performances.

New Physical and Chemical Treatments to Improve the Quantum Efficiency in Polymer Solar Cells

2008 ◽  
Vol 1091 ◽  
Author(s):  
Osamu Yoshikawa ◽  
Taro Sonobe ◽  
Takashi Sagawa ◽  
Susumu Yoshikawa
Keyword(s):  
Solar Cells ◽  
Bulk Heterojunction ◽  
Polymer Solar Cells ◽  
Short Circuit ◽  
Acid Methyl Ester ◽  
Single Mode ◽  
Short Circuit Current ◽  
Microwave Treatment ◽  
Short Circuit Current Density ◽  
Open Circuit

AbstractThe performance of the devices of bulk heterojunction polymer-based solar cells were investigated by using poly(3-hexylthiophene) (P3HT) and (6,6)-phenyl C61 butyric acid methyl ester (PCBM) as light absorption (viz. active) layer, with TiOx as interlayer as follows: ITO/PEDOT:PSS/P3HT-PCBM/TiOx/Al [1] through the treatment of microwave irradiation (single mode of 2.45 GHz, 800 W for 1, 2.5, or 5 min). Such treatments enabled to increase the short-circuit current density Jsc (from 4.53 mA cm−2 to 7.27 mA cm−2) and fill factor FF (from 0.41 to 0.66) of the cell, though the open circuit voltage Voc was decreased (from 0.61 V to 0.57 V) along the irradiation. Absorption spectra of P3HT-PCBM blended film before and after the microwave treatment were observed. Shoulders at 550 nm and 600 nm appeared after the irradiation. This result implies that the microcrystallization of P3HT was slightly promoted through the microwave treatment.

A Distributed Parameter Electromechanical Model for Cantilevered Piezoelectric Energy Harvesters

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
A. Erturk ◽  
D. J. Inman
Keyword(s):  
Electromechanical Coupling ◽  
Mechanical Response ◽  
Exact Analytical Solution ◽  
Short Circuit ◽  
Open Circuit ◽  
Distributed Parameter ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Cantilevered Beams ◽  
Power Outputs

Cantilevered beams with piezoceramic layers have been frequently used as piezoelectric vibration energy harvesters in the past five years. The literature includes several single degree-of-freedom models, a few approximate distributed parameter models and even some incorrect approaches for predicting the electromechanical behavior of these harvesters. In this paper, we present the exact analytical solution of a cantilevered piezoelectric energy harvester with Euler–Bernoulli beam assumptions. The excitation of the harvester is assumed to be due to its base motion in the form of translation in the transverse direction with small rotation, and it is not restricted to be harmonic in time. The resulting expressions for the coupled mechanical response and the electrical outputs are then reduced for the particular case of harmonic behavior in time and closed-form exact expressions are obtained. Simple expressions for the coupled mechanical response, voltage, current, and power outputs are also presented for excitations around the modal frequencies. Finally, the model proposed is used in a parametric case study for a unimorph harvester, and important characteristics of the coupled distributed parameter system, such as short circuit and open circuit behaviors, are investigated in detail. Modal electromechanical coupling and dependence of the electrical outputs on the locations of the electrodes are also discussed with examples.

scholarly journals Vibration Reduction of Mistuned Bladed Disks Via Piezoelectric-Based Resonance Frequency Detuning

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Garrett K. Lopp ◽  
Jeffrey L. Kauffman
Keyword(s):  
Resonance Frequency ◽  
Electromechanical Coupling ◽  
Short Circuit ◽  
Damping Ratio ◽  
Vibration Reduction ◽  
Sweep Rate ◽  
Open Circuit ◽  
Frequency Detuning ◽  
Blade Vibration ◽  
Direct Numerical Integration

This paper extends the resonance frequency detuning (RFD) vibration reduction approach to cases of turbomachinery blade mistuning. Using a lumped parameter mistuned blade model with included piezoelectric elements, this paper presents an analytical solution of the blade vibration in response to frequency sweep excitation; direct numerical integration confirms the accuracy of this solution. A Monte Carlo statistical analysis provides insight regarding vibration reduction performance over a range of parameters of interest such as the degree of blade mistuning, linear excitation sweep rate, inherent damping ratio, and the difference between the open-circuit (OC) and short-circuit (SC) stiffness states. RFD reduces vibration across all degrees of blade mistuning as well as the entire range of sweep rates tested. Detuning also maximizes vibration reduction performance when applied to systems with low inherent damping and large electromechanical coupling.

scholarly journals A Method for Parameter Identification of Composite Beam Piezoelectric Energy Harvester

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7213
Author(s):  
Xuhui Zhang ◽  
Chao Zhang ◽  
Lin Wang ◽  
Luyang Chen ◽  
Xiaoyu Chen ◽  
...  
Keyword(s):  
Parameter Identification ◽  
Composite Beam ◽  
Electromechanical Coupling ◽  
Energy Harvester ◽  
Short Circuit ◽  
Electromechanical Coupling Coefficient ◽  
Voltage Response ◽  
Backbone Curve ◽  
Response Characteristics ◽  
Piezoelectric Energy

This paper proposes a parameter identification method for the multiparameter identification study of the linear–arch composite beam piezoelectric energy harvester. According to the voltage response characteristics of the system under short-circuit conditions, the mechanical equation is solved by transient excitation, combined with the backbone curve theory and logarithmic attenuation method, to obtain the system’s linear damping, linear stiffness, and nonlinear stiffness. According to the voltage response characteristics of the system under open-circuit conditions, combined with the electrical equations, the system electromechanical coupling coefficient and equivalent capacitance coefficient are obtained; numerical simulation results show that the identification parameters have good accuracy. Finally, an experimental platform was built for verification, and the results show that the method has high accuracy and practicability.

Modal effective electromechanical coupling coefficient of shear-mode piezoceramic sandwich cantilevers with segmented multicore: Experimental and numerical assessments

2020 ◽  
pp. 107754632097290
Author(s):  
Pelin Berik ◽  
Ayech Benjeddou
Keyword(s):  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Performance Indicator ◽  
Numerical Models ◽  
Short Circuit ◽  
Smart Structures ◽  
Coupling Efficiency ◽  
Electromechanical Coupling Coefficient ◽  
Shear Mode ◽  
Effective Electromechanical Coupling Coefficient

Smart sandwich cantilevers with aluminum faces and single and double cores, formed by assembled shear-mode piezoceramic patches with same poling, are experimentally and numerically assessed for the first time. To measure the electromechanical coupling efficiency of such vibrating smart structures, the so-called modal effective electromechanical coupling coefficient is used as a performance indicator. Hence, it is first experimentally analyzed under different electric connections (short circuit, open circuit, series wiring, and parallel wiring) of the patches’ electrodes; then, it is numerically investigated for models with different refinements (equipotential constraints and bonding adhesives) using ABAQUS® three-dimensional finite element simulations. It is found that the experimental modal effective electromechanical coupling coefficient is low for the smart shear-mode piezoceramic single core sandwich but can be increased using multilayer designs, as confirmed by the smart shear-mode piezoceramic double core sandwich. Numerically, it is found that the electric connection has less influence on the modal effective electromechanical coupling coefficient evaluation than the equipotential constraints and adhesives modeling, in particular for the smart shear double core sandwich. The proposed two benchmarks can be used by the research community of smart structures, systems, and devices for validating new shear-mode response-based theories and numerical models or designing related engineering applications, such as shunted damping, energy harvesting, structural health monitoring, resonators, and filters.

scholarly journals Electrothermal Phenomena in Ferroelectrics

Actuators ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 93
Author(s):  
Kenji Uchino
Keyword(s):  
Thermal Diffusivity ◽  
Lead Zirconate Titanate ◽  
Electromechanical Coupling ◽  
Short Circuit ◽  
Electromechanical Coupling Factor ◽  
Lead Zirconate ◽  
Coupling Factor ◽  
Open Circuit ◽  
Comprehensive Knowledge ◽  
Poling Direction

Physical properties of lead-zirconate-titanate (PZT) ceramics change according to the initial electric poling process and electrical boundary conditions. This paper reports the electrothermal, piezothermal, and piezoelectric coupling phenomena in ferroelectrics from thermodynamics viewpoints, in particular, thermal property differences between unpoled and poled PZT’s in the poling direction for open circuit and short circuit conditions. We propose a new terminology, “secondary electrothermal” coupling factor kλ, which is analogous to the electromechanical coupling factor k, relating the elastic compliances under short- and open-circuit conditions, in order to explain the fact that the short-circuit condition exhibited the larger thermal diffusivity than the open-circuit condition. On the other hand, the unpoled specimen exhibits the lowest thermal diffusivity. This tutorial paper was authored for providing comprehensive knowledge on equilibrium and time-dependent thermodynamics in ferroelectrics.

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