In this paper ,the general solution of steady-state one dimensional asymmetric thermal stresses and electrical and mechanical displacements of a hollow cylinder made of functionally graded material and piezoelectric layers is developed .The material properties ,except the Poisson's ration, are assumed to depend on the variable radius and they are expressed as power functions of radius. The temp...

This paper studies free vibration of simply supported functionally graded beams with piezoelectric layers subjected to axial compressive loads. The Young's modulus of beam is assumed to be graded continuously across the beam thickness. Applying the Hamilton’s principle, the governing equation is established. Resulting equation is solved using the Euler’s Equation. The effects of the constituent...

Highly efficient light-emitting diodes (LEDs) emitting ultraviolet (UV), blue, green, amber and red light have been obtained through the use of InGaN active layers instead of GaN active layers. Red LEDs with an emission wavelength of 675 nm, whose emission energy was almost equal to the band-gap energy of InN, were fabricated. The dependence of the emission wavelength of the red LED on the curr...

A fully-coupled multiphysics modelling is applied for the problem of simultaneous active and passive reduction of noise generated by a thin panel under forced vibration providing many relevant results of various type (noise and vibration levels, necessary voltage for control signals, efficiency of the approach). The active approach is validated experimentally. To this end, the plate of panel is...

Multilayered microresonators commonly use sensitive coating or piezoelectric layers for detection of mass and gas. Most of these microresonators have a variable cross-section that complicates the prediction of their fundamental resonant frequency (generally of the bending mode) through conventional analytical models. In this paper, we present an analytical model to estimate the first resonant f...

T HE three-dimensional linear theory of elasticity is used to delineate the effect of the thickness, stiffness, and mass density of piezoelectric (PZT) layers on the ® rst ® ve natural frequencies of a simply supported graphite/epoxy laminated plate with PZT layers embedded in it. Platelike smart structures are usually made of PZT patches either embedded in or bonded to the bounding surfaces of...

We investigate the phonon mechanism for the orientational pinning of Wigner crystals and stripes in two-dimensional electron layers in GaAs matrices. We find the orientation of bilayer Wigner crystals on the (001), (111), (01̄1) and (311) interfaces versus the interlayer distance and determine the regions of parameters, where polydomain structures can emerge. For the stripe states in electron la...

The quarter-wavelength (hi4) acoustic matching layer is a vital component in medical ultrasonic transducers, which can bridge the large acoustic impedance mismatch between the piezoelectric material and the human body. .At high frequencies (>5OMHz), the hi4 matching layers become extremely thin and the characterization of its properties becomes very challenging. We report a novel method to meas...

There is evidence to support the claim that speedbreakers can cause accidents and injury. When a vehicle approaches a speed-breaker at a speed greater than some threshold velocity, the risk of accident or injury is substantial. Speed-breakers are inconspicuous in low visibility conditions, like at night, or when there is fog, rain or snow. This problem is particularly acute in developing countr...

This paper presents the investigation of a novel concept involving the combination of piezoelectric and new thin-film battery technology to form multifunctional self-charging, load-bearing energy harvesting devices. The proposed self-charging structures contain both power generation and energy storage capabilities in a multilayered, composite platform consisting of active piezoceramic layers fo...