This paper deals with the behavior of anti-plane shear crack in a piezoelectric layer bounded between two orthotropic half-planes within the framework of linear electroelasticity. The crack surfaces are assumed to be permeable or impermeable. The analysis is based on the stress fields caused by Volterra-type screw dislocation in the medium. Fourier transforms are used to reduce the dislocation ...

Electro-magneto-thermo-elastic response of a thick double-layered cylinder made from a homogeneous interlayer and a functionally graded piezoelectric material (FGPM) outer layer is investigated. Material properties of the FGPM layer vary along radius based on the power law distribution. The vessel is subjected to an internal pressure, an induced electric potential, a uniform magnetic field and ...

Piezoelectric nanogenerators (PNGs) are capable of converting energy from various mechanical sources into electric energy and have many attractive features such as continuous operation, replenishment and low cost. However, many researchers still have studied novel material synthesis and interfacial controls to improve the power production from PNGs. In this study, we report the energy conversio...

Starting from the general modal solutions for a homogeneous layer of arbitrary material and crystalline symmetry, a matrix formalism is developed to establish the semianalytical expressions of the surface impedance matrices (SIM) for a single piezoelectric layer. By applying the electrical boundary conditions, the layer impedance matrix is reduced to a unified elastic form whether the material ...

High-quality broadband ultrasound transducers yield superior imaging performance in biomedical ultrasonography. However, proper design to perfectly bridge the energy between the active piezoelectric material and the target medium over the operating spectrum is still lacking. Here, we demonstrate a new anisotropic cone-structured acoustic metamaterial matching layer that acts as an inhomogeneous...

OBJECTIVE The purpose of this study was to investigate the ultramorphology of the root surfaces induced by mechanical instrumentation performed using conventional curettes or piezoelectric scalers when used single-handedly or with a combined technique. MATERIAL AND METHODS Thirty single-rooted teeth were selected and divided into 3 groups: Group A, instrumentation with curettes; Group B instr...

Stability of functionally graded beams with piezoelectric layers subjected to axial compressive load that is simply supported at both ends is studied in this paper. The displacement field of beam is assumed based on first order shear deformation beam theory. Applying the Hamilton's principle, the governing equation is established. The influences of applied voltage, dimensionless geometrical par...

Air-coupled piezoelectric micromachined ultrasound transducer arrays, operating at ~190 kHz, have been fabricated utilizing an aluminum nitride piezoelectric layer. Improved fabrication processes have reduced the frequency variation seen in our previous work with single transducers resulting in arrays of transducers with resonant frequencies (fn) that match within the fractional half-power band...

Theoretical calculations have been performed to study the effects of piezoelectric fields in superlattice systems. The results show that cubic strained superlattices and quantum wells subjected to variable temperature and pressure exhibit changes in their piezoelectric fields. We consider superlattice systems grown in arbitrary directions, with a thickness smaller and larger than the critical t...

Piezoelectric sensors are widely used in accelerometers, for detecting failures in structures, and for vibration suppression systems among others. Such sensors can be manufactured in many different sizes, and packages to work in a variety of environments. The main characteristic of the piezoelectric material that allows for this effect is the conversion of mechanical to electrical energy. That ...