Analytical model of wave propagation in piezo thermo elastic multilayered PZT5A/LEMV/SWCNT/LEMV/PZT5A circular cylinder

In this study we revised the axisymmetric vibration of an infinite thermo piezoelectric composite circular hollow cylinder made of inner and outer thermo piezoelectric layer bonded together by a Linear Elastic Material with Voids (LEMV) and Single Walled carbon Nano Tube (SWCNT) is studied. The frequency equations are obtained for the traction free outer surface with continuity conditions at the interfaces. The equations of motion, heat and electric conduction also exactly solved. Numerical results are carried out for the inner and outer hollow piezoelectric layers bonded by LEMV and SWCNT layers. The dispersion curves are compared with core/LEMV/core, core cylinders

Vibration Analysis of Nonlinear Magneto Flexo Electric Mass Sensor Carbon Nanotube Resting on Elastic Substrate

The present paper is dedicated to study the nonlinear ultrasonic waves in a magneto-flexo-thermo elastic armchairsingle-walled carbon nanotube with mass sensors resting on polymer matrix. Here the small-scale effect is captured by Eringen’s nonlocal elasticity theory. After developing the formal solution of the mathematical model consisting of partial differential equations, the frequency equations have been analyzed numerically by using the nonlinear foundations supported by Winkler-Pasternak model. The solution is obtained by ultrasonic wave dispersion relations. Parametric work is carried out to scrutinize the influence of the non local scaling, magneto-flexo-mechanical loadings, foundation parameters, attached mass, various boundary condition and length on the dimensionless frequency of nanotube. It is noticed that the boundary conditions, nonlocal parameter, attached mass and tube geometrical parameters have significant effects on dimensionless frequency of nano tubes

Nonlinear magneto-thermo-elastic vibration of mass sensor armchair carbon nanotube resting on an elastic substrate

Abstract The present paper aims at studying the nonlinear ultrasonic waves in a magneto-thermo-elastic armchair single-walled (SW) carbon nanotube (CNT) with mass sensors resting on a polymer substrate. The analytical formulation accounts for small scale effects based on the Eringen's nonlocal elasticity theory. The mathematical model and its differential equations are solved theoretically in terms of dimensionless frequencies while assuming a nonlinear Winkler-Pasternak-type foundation. The solution is obtained by means of ultrasonic wave dispersion relations. A parametric work is carried out to check for the effect of the nonlocal scaling parameter, together with the magneto-mechanical loadings, the foundation parameters, the attached mass, boundary conditions and geometries, on the dimensionless frequency of nanotubes. The sensitivity of the mechanical response of nanotubes investigated herein, could be of great interest for design purposes in nano-engineering systems and devices

Influence of rotation on transversely isotropic piezoelectric rod coated with a thin film

CITATION: Selvamani, R. & Makinde, O. D. 2018. Influence of rotation on transversely isotropic piezoelectric rod coated with a thin film. Engineering Transactions, 66(3):211–227, doi:10.24423/EngTrans.859.20180726.The original publication is available at http://et.ippt.gov.plIn this paper, the influence of rotation on axisymmetric waves of a piezoelectric rod coated with a thin film is studied using constitutive form linear theory elasticity and piezo-electric equations. Potential functions are introduced to uncouple the equations of motion in radial and axial directions. The surface area of the rod is coated by a perfectly conducting material. The frequency equations are obtained for longitudinal and flexural modes of vibration and are studied numerically for PZT-4 ceramics. The computed non-dimensional frequency, phase velocity, relative frequency shift, electromechanical coupling and electric displacement are presented in the form of dispersion curves. This type of study is important in the construction of rotating sensors and gyroscope.http://et.ippt.gov.pl/index.php/et/article/view/859Publisher's versio

Nonlinear Low-Velocity Impact Response of Multi Scale Carbon Fiber-Epoxy Reinforced Nanocomposite Plates Using Finite Element Method

In this study, the effect of addition of carbon nanotube on the nonlinear low-velocity impact response thermo elastic ofcarbon fiber/epoxy composites is performed using the finite element method. The effective material properties of the multiscale composite are calculated using Halpin-Tsai equations and fiber micromechanics in hierarchy. The governing equations are derived based on higher-order shear deformation plate theory(HSDT) and von Kármán geometrical nonlinearity. The carbon nanotubes are assumed to be uniformly distributed and randomly oriented through the epoxy resin matrix. Contact force between the impactor and the plate is obtained with the aid of the modified nonlinear Hertzian contact law models. After examining the validity of the present work, the effects of the weight percentage of single-walled carbon nanotubes(SWCNTs) and multi-walled carbon nanotubes(MWCNTs), nanotube aspect ratio, volume fraction of fibers, plate aspect ratio and initial velocity of the impactor on the contact force, indentation, and central deflection of CNT reinforced multi-phase laminated composite plate are studied in detailsIn this study, the effect of addition of carbon nanotube on the nonlinear low-velocity impact response thermo elastic ofcarbon fiber/epoxy composites is performed using the finite element method. The effective material properties of the multiscale composite are calculated using Halpin-Tsai equations and fiber micromechanics in hierarchy. The governing equations are derived based on higher-order shear deformation plate theory(HSDT) and von Kármán geometrical nonlinearity. The carbon nanotubes are assumed to be uniformly distributed and randomly oriented through the epoxy resin matrix. Contact force between the impactor and the plate is obtained with the aid of the modified nonlinear Hertzian contact law models. After examining the validity of the present work, the effects of the weight percentage of single-walled carbon nanotubes(SWCNTs) and multi-walled carbon nanotubes(MWCNTs), nanotube aspect ratio, volume fraction of fibers, plate aspect ratio and initial velocity of the impactor on the contact force, indentation, and central deflection of CNT reinforced multi-phase laminated composite plate are studied in detail

Nonlocal state-space strain gradient wave propagation of magneto thermo piezoelectric functionally graded nanobeam

In this work, the state -space nonlocal strain gradient theory is used for the vibration analysis of magneto thermo piezoelectric functionally graded material (FGM) nanobeam. An analysis of FGM constituent properties is stated by using the power law relations. The refined higher order beam theory and Hamilton’s principle have been used to obtain the motion equations. Besides, the governing equations of the magneto thermo piezoelectric nanobeam are extracted by developed nonlocal state-space theory. And to solve the wave propagation problems, the analytical wave dispersion method is used. The effect of magnetic potential, temperature gradient, and electric voltage in variant parameters are presented in graph

Nonlinear magneto-thermo-elastic vibration of mass sensor armchair carbon nanotube resting on an elastic substrate

The present paper aims at studying the nonlinear ultrasonic waves in a magneto-thermo-elastic armchair single-walled (SW) carbon nanotube (CNT) with mass sensors resting on a polymer substrate. The analytical formulation accounts for small scale effects based on the Eringen’s nonlocal elasticity theory. The mathematical model and its differential equations are solved theoretically in terms of dimensionless frequencies while assuming a nonlinear Winkler-Pasternak-type foundation. The solution is obtained by means of ultrasonic wave dispersion relations. A parametric work is carried out to check for the effect of the nonlocal scaling parameter, together with the magneto-mechanical loadings, the foundation parameters, the attached mass, boundary conditions and geometries, on the dimensionless frequency of nanotubes. The sensitivity of the mechanical response of nanotubes investigated herein, could be of great interest for design purposes in nano-engineering systems and devices

Stability analysis of hygro-magneto-flexo electric functionally graded nanobeams embedded on visco-Pasternak foundation

In this paper, the stability analysis of hygro-magneto-flexo electricity (HMFE) on functionally graded (FG) viscoelastic nanobeams accommodate in viscoelastic foundation based on nonlocal elasticity theory is addressed. Higher order refined beam theory is used for the expositions of the displacement components and the viscoelastic foundation is included with Winkler-Pasternak layer. The governing equations of nonlocal gradient viscoelastic FG nanobeam are obtained by Hamilton\u27s principle and solved by administrating an analytical solution for different boundary conditions. A power-law index model is adopted to describe continuous variation of temperature-dependent material properties of FG nanobeam. A parametric study is presented to inquire the effect of the nonlocal parameter on various physical variables