Improvement of electromechanical coupling coefficient in shear-mode of piezoelectric ceramics

2019 ◽  
Vol 45 (2) ◽  
pp. 1496-1502 ◽  
Author(s):  
Lei Qin ◽  
Junbo Jia ◽  
Minkyu Choi ◽  
Kenji Uchino
2005 ◽  
Vol 888 ◽  
Author(s):  
Qiang Chen ◽  
Dejun Lan ◽  
Yi Chen ◽  
Zhuo Xu ◽  
Xi Yue ◽  
...  

ABSTRACTLithium sodium potassium niobate (Li, Na, K)NbO3 (LNKN) piezoelectric ceramics were prepared by using conventional solid state process. The phase structures of LNKN ceramics were characterized by x-ray diffraction (XRD). The dielectric properties of LNKN ceramics have been also studied at different temperature and frequency. It was found that LNKN ceramics have high Curie temperature Tc(about 460°C), and relatively high piezoelectric constant d33 (∼200pC/N) and high electromechanical coupling coefficient kp(∼0.40). Both of the piezoelectric constant d33 and electromechanical coupling coefficient kp of LNKN ceramics decreased with the increasing of sintering temperature. The piezoelectric property dependence of composition of LNKN ceramics has also been studied.


2020 ◽  
pp. 107754632097290
Author(s):  
Pelin Berik ◽  
Ayech Benjeddou

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.


2007 ◽  
Vol 102 (2) ◽  
pp. 024110 ◽  
Author(s):  
Takahiko Yanagitani ◽  
Masato Kiuchi ◽  
Mami Matsukawa ◽  
Yoshiaki Watanabe

2019 ◽  
Vol 553 (1) ◽  
pp. 43-50
Author(s):  
Siyu Huang ◽  
Xiang Xia ◽  
Xuezheng Ruan ◽  
Xue Shi ◽  
Liaoying Zheng ◽  
...  

2016 ◽  
Vol 848 ◽  
pp. 339-343
Author(s):  
Xiao Kun Zhao ◽  
Bo Ping Zhang ◽  
Lei Zhao ◽  
Li Feng Zhu

The modified behavior of the phase transition temperatures (TO-T and/or TC) between orthorhombic (O), tetragonal (T) and cubic (C) that caused by doping Sb5+ in (Li0.052Na0.493K0.455)(Nb1-xSbx)O3 (LNKNSx) ceramics was reported in the present investigation. The results show that differing from the insensitive TO-T to the Sb5+ content, TC splits into two peaks TCI and TCII when doping Sb5+. The decreased TCI by raising x may be ascribed to the Sb-rich grains and the settled TCII round 480 °C resulting from the Sb-lack ones. The enhanced piezoelectric coefficient d33 value of 263 pC/N and planar mode electromechanical coupling coefficient kp value of 42.5% at x=0.052 can be attributed to the polymorphic phase boundary (PPB) behavior with an appropriate ratio between T and O phases without any second phase.


2018 ◽  
Vol 29 (20) ◽  
pp. 3949-3959 ◽  
Author(s):  
Adriane G Moura ◽  
Alper Erturk

We establish and analyze an analytical framework by accounting for both the piezoelectric and flexoelectric effects in bimorph cantilevers. The focus is placed on the development of governing electroelastodynamic piezoelectric–flexoelectric equations for the problems of resonant energy harvesting, sensing, and actuation. The coupled governing equations are analyzed to obtain closed-form frequency response expressions via modal analysis. The combined piezoelectric–flexoelectric coupling coefficient expression is identified and its size dependence is explored. Specifically, a typical atomistic value of the flexoelectric constant for barium titanate is employed in the model simulations along with its piezoelectric constant from the existing literature. It is shown that the effective electromechanical coupling of a piezoelectric material, such as barium titanate, is significantly enhanced for thickness levels below 100 nm. The electromechanical coupling coefficient of a barium titanate bimorph cantilever increases from the bulk piezoelectric value of 0.065 to the combined piezoelectric–flexoelectric value exceeding 0.3 toward nanometer thickness level. Electromechanical frequency response functions for resonant power generation and dynamic actuation also capture the size-dependent enhancement of the electromechanical coupling. The analytical framework given here can be used for parameter identification and design of nanoscale cantilevers that can be used as energy harvesters, sensors, and actuators.


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