Memorias de investigación
Communications at congresses:
FEA study of shear mode decoupling in lead-free piezoceramic plates

Research Areas
  • Physics chemical and mathematical

A number of methods to determine the coefficients of poled piezoceramics from the analysis of the complex impedance curves at electrically excited electromechanical resonances were developed and are in use at present [1]. For the validity of these methods, the analysed resonance must be unimodal, which for the shear resonance of the standard, in-plane poled, plate is a problem that cannot be solved. The automatic iterative method (Spanish CSIC) was implemented for all the resonances and resonator shapes needed for their complete matrix characterization [1], namely: radial and thickness extensional resonances of thin disk, thickness poled; and length extensional resonance of a long bar, length poled. Besides, and for the shear parameters determination, due to the limitations of the standard plate, the iterative method has been implemented for the shear resonance of, thickness poled and longitudinally excited plate [2]. In this way, the full set of material coefficients was determined for one of the most promissing candidates for replacement of lead-circonate titanate: the lead-free bismuth-sodium-barium titanate at the Morphotropic Phase Boundary: (1-x)(Bi0.5Na0.5)TiO3?xBaTiO3 with x=0.06 (BNBT6) [3]. 3-D modeling carried out by Finite Element Analysis (FEA), is nowadays currently used for design of piezoceramics applications. It has also been used as quality criteria of the complete set of material data, which is needed to stablish the constitutive equations of the piezoelectricity used for the modeling [2]. FEA modelling is used in this work to study the modes of resonance that are excited together with the main shear resonance in, thickness poled and longitudinally excited, BNBT6 plates. An study as a function of the variations of the dimensions of the plate (t=thickness, L, w= lateral dimensions, where the distance between electrodes for the electrical excitation=w) was made to study the coupling phenomena and seed light on the origin of the lateral modes.
XIV Reunión Nacional de Electrocerámica
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Research Group, Departaments and Institutes related
  • Creador: Departamento: Electrónica Física
  • Departamento: Ingeniería Telemática y Electrónica