A. M. Abd-Alla

Bio: A. M. Abd-Alla is an academic researcher from Sohag University. The author has contributed to research in topics: Thermoelastic damping & Magnetic field. The author has an hindex of 10, co-authored 41 publications receiving 271 citations.

Influences of Rotation, Magnetic Field, Initial Stress, and Gravity on Rayleigh Waves in a Homogeneous Orthotropic Elastic Half-Space

Abstract: The aim of this paper is to investigate the influences of rotation, magnetic field, initial stress, and gravity field on Rayleigh waves in a homogeneous orthotropic elastic medium. The government equations is solved by Lame’s potential and obtained the frequency equation which determines the velocity of Rayleigh waves, including rotation, initial stress, gravity field, and magnetic field, in a homogeneous orthotropic elastic medium has been investigated. Numerical results analyzing the frequency equation are discussed and presented graphically. The results indicate that the effect of rotation, initial stress, magnetic field, and gravity field on Rayleigh wave velocity are very pronounced. Comparison are made with the results in the absence of rotation, initial stress, magnetic field and gravity field.

Effects of rotation and gravity on an electro-magneto-thermoelastic medium with diffusion and voids by using the Lord-Shulman and dual-phase-lag models

Abstract: The effects of rotation and gravity on an electro-magneto-thermoelastic medium with diffusion and voids in a generalized thermoplastic half-space are studied by using the Lord-Shulman (L-S) model and the dual-phase-lag (DPL) model The analytical solutions for the displacements, stresses, temperature, diffusion concentration, and volume fraction field with different values of the magnetic field, the rotation, the gravity, and the initial stress are obtained and portrayed graphically The results indicate that the effects of gravity, rotation, voids, diffusion, initial stress, and electromagnetic field are very pronounced on the physical properties of the material

Effect of rotation and gravity on the reflection of P-waves from thermo-magneto-microstretch medium in the context of three phase lag model with initial stress

Abstract: In this paper the linear theory of the thermoelasticity has been employed to study the effect the reflection of plane harmonic waves from a semi-infinite elastic solid under the effect of the magnetic field , rotation, initial stress and gravity. The medium under consideration is traction free, homogeneous, isotropic, as well as with three-phase-lag. The normal mode analysis is used to solve the resulting non-dimensional coupled equations. The expressions for the reflection coefficients, which are the relations of the amplitudes of the reflected waves to the amplitude of the incident waves, are obtained similarly, the reflection coefficient ratio variations with the angle of incident under different conditions are shown graphically. Comparisons are made with the results predicted by different theories Lord-Shulman theory (L-S), the Green-Naghdi theory of type III (G-N III) and the three-phase-lag model in the absence and presence of a magnetic field, rotation, initial stress and gravity. The results indicate that the effect of rotation, magnetic field, initial stress and gravity field are very pronounced.

Photothermal and void effect of a semiconductor rotational medium based on Lord–Shulman theory

Abstract: In this article the photothermal and void parameters of a semiconductor rotational medium are investigated when there is a fixed thermal relaxation time We obtain the displacement, temperature, st

A novel solution of fractional order heat equation for photothermal waves in a semiconductor medium with a spherical cavity

Abstract: In this paper, we consider a one dimensional problem of waves in a thermoelastic infinite medium with a spherical cavity. We are concerned with the study a new model of fractional order heat conduction law for a spherical cavity of a semiconductor medium. The governing equations are solved under the effect of the theory of coupled plasma, elastic, thermal waves through a photothermal process. The inner surface of the cavity is taken traction free with thermal shock. Time-dependence is removed by Laplace transform technique to governing equations. This method has been used to get the exact expression of some physical quantities, thermal activation coupling parameters and illustrated graphically.

Effect of the rotation, magnetic field and initial stress on peristaltic motion of micropolar fluid

Abstract: In this work, the effect of magnetic field, rotation and initial stress on peristaltic motion of micropolar fluid in a circular cylindrical flexible tube with viscoelastic or elastic wall properties has been considered. Runge–Kutta technique are used. Runge–Kutta method is developed to solve the governing equations of motion resulting from a perturbation technique for small values of amplitude ratio. The time mean axial velocity profiles are presented for the case of free pumping and analyzed to observe the influence of wall properties, magnetic field, rotation and initial stress for various values of micropolar fluid parameters. In the case of viscoelastic wall, the effect of viscous damping on mean flow reversal at the boundary is seen. The numerical results of the time mean velocity profile are discussed in detail for homogeneous fluid under the effect of wall properties, magnetic field, initial stress and rotation for different cases by figures. The results indicate that the effect of wall properties, rotation, initial stress and magnetic field are very pronounced. Numerical results are given and illustrated graphically.

Propagation of Rayleigh waves in a rotating orthotropic material elastic half-space under initial stress and gravity

Abstract: This paper aims to investigate the influence of rotation, initial stress and gravity field on the propagation of Rayleigh waves in a homogeneous orthotropic elastic medium. The government equations and Lame’s potentials are used to obtain the frequency equation which determines the velocity of Rayleigh waves, including rotation, initial stress and gravity field, in a homogeneous, orthotropic elastic medium has been investigated. The numerical results analyzing the frequency equation are discussed and presented graphically. It is important to note that the Rayleigh wave velocity in an orthotropic elastic medium increases a considerable amount in comparison to the Rayleigh wave velocity in an isotropic material. The results indicate that the effects of rotation, initial stress and gravity field on Rayleigh wave velocity are very pronounced.

Propagation of Rayleigh waves in magneto-thermo-elastic half-space of a homogeneous orthotropic material under the effect of rotation, initial stress and gravity field

Abstract: The propagation of magneto-thermoelastic plane waves in an initially stressed, homogeneous orthotropic, conducting half-space under a magnetic field, rotation and gravity field have been investigated. The generalized theory of thermoelasticity is employed, by assuming the mechanical behavior as dynamic, to study the problem. The Lame’s potential is used to obtain the frequency equation that determines the velocity of Rayleigh waves that obtained as a real part and the attenuation coefficient as an imaginary part under the rotation, magnetic field, initial stress and gravity field. Numerical results have been given and illustrated graphically for each case considered. Dispersion curves of wave propagation are represented graphically in different theories of thermoelasticity. The results indicate that the effect of rotation, initial stress and gravity field are very pronounced. Comparison is made with the results predicted by the theory of thermoelasticity in the absence of rotation, initial stress and grav...