Guided Waves Propagating in a Bi-Layer System Consisting of a Piezoelectric Plate and a Dielectric Fluid Layer

Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, Taiwan R.O.C.
IEEE transactions on ultrasonics, ferroelectrics, and frequency control (Impact Factor: 1.51). 08/2011; 58(8):1612-8. DOI: 10.1109/TUFFC.2011.1988
Source: PubMed


This study employs a theoretical modeling and an experimental measurement for investigating the dispersion behavior of guided waves propagating in a bi-layer system consisting of a piezoelectric plate and a dielectric fluid layer. The theoretical model is based on a recursive asymptotic stiffness matrix method (RASM) with the fluid layer modeled as an equivalent elastic body. A laser ultrasound technique is used to measure the dispersion relations of the bi-layer system. Behaviors of mode couplings between guided modes propagating in the piezoelectric plate and those in fluid layer are characterized in the modeling and measurements. Dispersion behaviors of guided modes propagating in the bi-layer system are discussed for varying fluid thicknesses. For all of the investigated cases, the theoretical modeled dispersion spectra agree well with the measurements.

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    • "They depend on the thicknesses, the mass densities, the plate elastic coefficients C ij and the fluid longitudinal velocity c f . However, for simplicity, following Simonetti (2004) and Wu and Yang (2011), the bilayer waveguide is assumed in a first approximation to behave mainly like two decoupled waveguides. It implies that a measured guided mode wavenumber k exp corresponds to either a plate k p or a fluid wavenumber k f . "
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