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 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.

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.

Relaxor Single Crystals with Giant k31 Mode

2006 ◽  
Vol 45 ◽  
pp. 2412-2421
Author(s):  
Toshio Ogawa
Keyword(s):  
Single Crystal ◽  
Electromechanical Coupling ◽  
Impedance Measurement ◽  
Hysteresis Loops ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Poling Direction ◽  
Length Direction ◽  
Relaxor Single Crystals ◽  
The Relationship

Giant electromechanical coupling factor of k31 mode over 86% was found for (100) Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 and (110) Pb[(Mg1/3Nb2/3)0.74Ti0.26]O3 single-crystal plates poled in the [100] and [110] directions, respectively. The P-E hysteresis loops in the single-crystal plates with giant k31 became asymmetric. Furthermore, the frequency response of impedance in these plates with giant k31 consisted of a single vibration in the length direction. A mechanism to realize giant k31 can be explained by the relationship between the crystal plane and poling direction. In addition, the existence of giant piezoelectric d31 constant was proven by the strain measurement as well as by the impedance measurement.

scholarly journals Surface Wave Speed of Functionally Graded Magneto-Electro-Elastic Materials with Initial Stresses

2014 ◽  
Vol 44 (3) ◽  
pp. 49-64 ◽  
Author(s):  
Li Li ◽  
P. J. Wei
Keyword(s):  
Surface Wave ◽  
Boundary Conditions ◽  
Elastic Material ◽  
Short Circuit ◽  
Equations Of Motion ◽  
Open Circuit ◽  
Functionally Graded ◽  
Initial Stresses ◽  
Shear Surface ◽  
Traction Boundary Conditions

Abstract The shear surface wave at the free traction surface of half- infinite functionally graded magneto-electro-elastic material with initial stress is investigated. The material parameters are assumed to vary ex- ponentially along the thickness direction, only. The velocity equations of shear surface wave are derived on the electrically or magnetically open circuit and short circuit boundary conditions, based on the equations of motion of the graded magneto-electro-elastic material with the initial stresses and the free traction boundary conditions. The dispersive curves are obtained numerically and the influences of the initial stresses and the material gradient index on the dispersive curves are discussed. The investigation provides a basis for the development of new functionally graded magneto-electro-elastic surface wave devices.

scholarly journals Effect of Polymer-Ceramic Fibre Interphase Design on Coupling Factor in Low Fibre Volume Content Piezoelectric Composites

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Tony Lusiola ◽  
Sophie Oberle ◽  
Lovro Gorjan ◽  
Frank Clemens
Keyword(s):  
Epoxy Resin ◽  
Lead Zirconate Titanate ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Factor ◽  
Polymer Coatings ◽  
Coupling Factor ◽  
Fibre Volume ◽  
Resin Matrix ◽  
Ceramic Fibre ◽  
Soft Polymer

In this work, we investigated different short molecule polymer coatings in piezoelectric ceramic-polymer composites with low fibre volume contents. Modifying the interphase between the piezoelectric PZT (lead zirconate titanate) fibre and the epoxy matrix thus enhances the electromechanical coupling factor for 1–3 ultrasound transducers with low fibre contents. It is known that the electromechanical coupling factor can be increased by precoating a ceramic fibre with a soft interlayer polymer [1-1-3]. In this paper, we investigate the so-called 1-1-1-3 composites composed of a ferroelectric ceramic fibre (core), a soft polymer layer (e.g., fatty acids, amides, waxes, or oils), an epoxy resin shell, and an epoxy resin matrix. Some soft polymer layers allowed the free movement of the ferroelectric fibres reducing blocking or clamping by the inactive polymeric matrix, resulting in higher electromechanical coupling factors (kt) for composites with low fibre volume contents. Using an oil-based interlayer, the dielectric constant can be significantly increased. The lowest fibre push-out stress could be achieved with the paraffin interlayer; however, no correlation with the coupling factor could be observed.

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.

scholarly journals Properties ofPb(Zr,Ti)O3ultrathin films under stress-free and open-circuit electrical boundary conditions

2004 ◽  
Vol 70 (22) ◽  
Author(s):  
Emad Almahmoud ◽  
Yulia Navtsenya ◽  
Igor Kornev ◽  
Huaxiang Fu ◽  
L. Bellaiche
Keyword(s):  
Boundary Conditions ◽  
Open Circuit ◽  
Electrical Boundary Conditions

scholarly journals Energy Harvester Based on the Synchronization Phenomenon of a Circular Cylinder

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Junlei Wang ◽  
Jingyu Ran ◽  
Zhien Zhang
Keyword(s):  
Circular Cylinder ◽  
Lead Zirconate Titanate ◽  
Electromechanical Coupling ◽  
Lead Zirconate ◽  
Open Circuit ◽  
Fluid Field ◽  
Voltage Output ◽  
Lift And Drag ◽  
Lift And Drag Coefficient ◽  
High Level

A concept of generating power from a circular cylinder undergoing vortex-induced vibration (VIV) was investigated. Two lead zirconate titanate (PZT) beams which had high power density were installed on the cylinder. A theoretical model has been presented to describe the electromechanical coupling of the open-circuit voltage output and the vibration amplitudes based on a second-order nonlinear Van der pol equation and Gauss law. A numerical computation was applied to measure the capacity of the power generating system. The lift and drag coefficient and the vortex shedding frequency were obtained to verify how the nondimensional parameter reduced velocityUraffects the fluid field. Meanwhile, a single-degree of freedom system has been added to describe the VIV, presynchronization, and synchronization together with postsynchronization regimes of oscillating frequencies. And the amplitudes of the vibration have been obtained. Finally, the vibrational amplitudes and the voltage output could go up to a high level in the synchronization region. The maximum value of the voltage output and the corresponding reduced velocityUrwere 8.42 V and 5.6, respectively.

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