Two-temperature thermoelastic surface waves in micropolar thermoelastic media via dual-phase-lag model

Abouelregal, A.E.,Zenkour, A.M. Techno-Press 2017 Advances in aircraft and spacecraft science Vol.4 No.6

This article is concerned with a two-dimensional problem of micropolar generalized thermoelasticity for a half-space whose surface is traction-free and the conductive temperature at the surface of the half-space is known. Theory of two-temperature generalized thermoelasticity with phase lags using the normal mode analysis is used to solve the present problem. The formulas of conductive and mechanical temperatures, displacement, micro-rotation, stresses and couple stresses are obtained. The considered quantities are illustrated graphically and their behaviors are discussed with suitable comparisons. The present results are compared with those obtained according to one temperature theory. It is concluded that both conductive heat wave and thermodynamical heat wave should be separated. The two-temperature theory describes the behavior of particles of elastic body more real than one-temperature theory.

Variability of thermal properties for a thermoelastic loaded nanobeam excited by harmonically varying heat

Abouelregal, A.E.,Zenkour, A.M. Techno-Press 2017 Smart Structures and Systems, An International Jou Vol.20 No.4

This work produces a new model of nonlocal thermoelastic nanobeams of temperature-dependent physical properties. A nanobeam is excited by harmonically varying heat and subjected to an exponential decaying time varying load. The analytical solution is obtained by means of Laplace transform method in time domain. Inversions of transformed solutions have been preceded by using calculus of residues. Effects of nonlocal parameter, variability thermal conductivity, varying load and angular frequency of thermal vibration on studied fields of nanobeam are investigated and discussed.

Thermoelastic deformation properties of non-localized and axially moving viscoelastic Zener nanobeams

Ahmed E. Abouelregal,Badahi Ould Mohamed,Hamid M. Sedighi Techno-Press 2024 Advances in nano research Vol.16 No.2

This study aims to develop explicit models to investigate thermo-mechanical interactions in moving nanobeams. These models aim to capture the small-scale effects that arise in continuous mechanical systems. Assumptions are made based on the Euler-Bernoulli beam concept and the fractional Zener beam-matter model. The viscoelastic material law can be formulated using the fractional Caputo derivative. The non-local Eringen model and the two-phase delayed heat transfer theory are also taken into account. By comparing the numerical results to those obtained using conventional heat transfer models, it becomes evident that non-localization, fractional derivatives and dual-phase delays influence the magnitude of thermally induced physical fields. The results validate the significant role of the damping coefficient in the system's stability, which is further dependent on the values of relaxation stiffness and fractional order.

Effects of variable harmonic heat and photothermal elasticity on an infinitely long solid semiconductor cylinder

Zenkour A. M.,Abouelregal A. E. 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.79 No.8

In this research, photo-thermoelasticity theory with phase lags was introduced and applied to an infinite semiconductor body in the form of a solid cylinder. The body is constricted and exposed to harmonic shifting heat. The essential equations overseeing the problem are unraveled utilizing the Laplace transform. To locate the analytical formulae of the physical amounts and to discover inverse Laplace transforms, we utilized a numerical technique. The detailed examination of the impacts of phase lags and the angular frequency of the thermal vibration on the absolute temperature, stresses, absolute carrier density, and displacement is considered.

Decaying temperature and dynamic response of a thermoelastic nanobeam to a moving load

Zenkour, Ashraf M.,Abouelregal, Ahmed E. Techno-Press 2018 Advances in computational design Vol.3 No.1

The decaying temperature and dynamic response of a thermoelastic nanobeam subjected to a moving load has been investigated in the context of generalized theory of nonlocal thermoelasticity. The transformed distributions of deflection, temperature, axial displacement and bending moment are obtained by using Laplace transformation. By applying a numerical inversion method, the results of these fields are then inverted and obtained in the physical domain. Also, for a particular two models, numerical results are discussed and presented graphically. Some specific and special results are derived from the current study.

The effect of two temperatures on a FG nanobeam induced by a sinusoidal pulse heating

Zenkour, Ashraf M.,Abouelregal, Ahmed E. Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.51 No.2

The present investigation is concerned with the effect of two temperatures on functionally graded (FG) nanobeams subjected to sinusoidal pulse heating sources. Material properties of the nanobeam are assumed to be graded in the thickness direction according to a novel exponential distribution law in terms of the volume fractions of the metal and ceramic constituents. The upper surface of the FG nanobeam is fully ceramic whereas the lower surface is fully metal. The generalized two-temperature nonlocal theory of thermoelasticity in the context of Lord and Shulman's (LS) model is used to solve this problem. The governing equations are solved in the Laplace transformation domain. The inversion of the Laplace transformation is computed numerically using a method based on Fourier series expansion technique. Some comparisons have been shown to estimate the effects of the nonlocal parameter, the temperature discrepancy and the pulse width of the sinusoidal pulse. Additional results across the thickness of the nanobeam are presented graphically.

State space approach for the vibration of nanobeams based on the nonlocal thermoelasticity theory without energy dissipation

A. M. Zenkour,A. E. Abouelregal,K. A. Alnefaie,N. H. Abu-Hamdeh,A. A. Aljinaidi,E. C. Aifantis 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.7

In this article, an Euler-Bernoulli beam model based upon nonlocal thermoelasticity theory without energy dissipation is used to studythe vibration of a nanobeam subjected to ramp-type heating. Classical continuum theory is inherently size independent, while nonlocalelasticity exhibits size dependence. Among other things, this leads to a new expression for the effective nonlocal bending moment ascontrasted to its classical counterpart. The thermal problem is addressed in the context of the Green-Naghdi (GN) theory of heat transportwithout energy dissipation. The governing partial differential equations are solved in the Laplace transform domain by the state spaceapproach of modern control theory. Inverse of Laplace transforms are computed numerically using Fourier expansion techniques. Theeffects of nonlocality and ramping time parameters on the lateral vibration, temperature, displacement and bending moment are discussed.

Thermoelastic interaction in functionally graded nanobeams subjected to time-dependent heat flux

Ashraf M. Zenkour,Ahmed E. Abouelregal 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.18 No.4

This paper investigates the vibration phenomenon of a nanobeam subjected to a time-dependent heat flux. Material properties of the nanobeam are assumed to be graded in the thickness direction according to a novel exponential distribution law in terms of the volume fractions of the metal and ceramic constituents. The upper surface of the functionally graded (FG) nanobeam is pure ceramic whereas the lower surface is pure metal. A nonlocal generalized thermoelasticity theory with dual-phase-lag (DPL) model is used to solve this problem. The theories of coupled thermoelasticity, generalized thermoelasticity with one relaxation time, and without energy dissipation can extracted as limited and special cases of the present model. An analytical technique based on Laplace transform is used to calculate the variation of deflection and temperature. The inverse of Laplace transforms are computed numerically using Fourier expansion techniques. The effects of the phase-lags (PLs), nonlocal parameter and the angular frequency of oscillation of the heat flux on the lateral vibration, the temperature, and the axial displacement of the nanobeam are studied.

The effect of two temperatures on a FG nanobeam induced by a sinusoidal pulse heating

Ashraf M. Zenkour,Ahmed E. Abouelregal 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.51 No.2

The present investigation is concerned with the effect of two temperatures on functionally graded (FG) nanobeams subjected to sinusoidal pulse heating sources. Material properties of the nanobeam are assumed to be graded in the thickness direction according to a novel exponential distribution law in terms of the volume fractions of the metal and ceramic constituents. The upper surface of the FG nanobeam is fully ceramic whereas the lower surface is fully metal. The generalized two-temperature nonlocal theoryof thermoelasticity in the context of Lord and Shulman's (LS) model is used to solve this problem. The governing equations are solved in the Laplace transformation domain. The inversion of the Laplace transformation is computed numerically using a method based on Fourier series expansion technique. Somecomparisons have been shown to estimate the effects of the nonlocal parameter, the temperature discrepancy and the pulse width of the sinusoidal pulse. Additional results across the thickness of the nanobeam are presented graphically.

Generalized thermodiffusion for an unbounded body with a spherical cavity subjected to periodic loading

A. M. Zenkour,D. S. Mashat,A. E. Abouelregal 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.3

In this paper, a general solution to the field equations of generalized thermodiffusion in an infinite thermoelastic body with a spherical cavity has been obtained in the context of the theory of generalized thermoelastic diffusion. The bounding surface of the sphere is subjected to periodic loading and the temperature and chemical potential are assumed to be zero on the curved surface. The generalized theory of thermoelasticity is applied to account for finite velocity of heat propagation. The closed form solutions for distributions of displacement, temperature and stresses are obtained. The solutions valid in the case of small frequency are deduced and the results are compared with the corresponding results obtained in other generalized thermoelasticity theories. Numerical results applicable to a copper-like material are also presented graphically and the nature of variations of the physical quantities with radial coordinate and with frequency of vibration is analyzed.