Thermal shock behaviour on generalized thermoelastic semi-infinite medium with moving heat source under Green Naghdi-III model

The present article deals with the thermal shock response in an isotropic thermoelastic medium with a moving heat source. In this context Green and Naghdi type III model of generalized thermoelasticity theory is considered. The basic equations are expressed as vector-matrix differential equation form. The considered formulation is applied to a semi-infinite solid space. The analytical formulations of the problem in the Laplace transform domain have been solved by eigenvalue approach technique. The inversion of Laplace transform is completed by Zakian method. The variation of the temperature, displacement and stress distributions for different values of time and heat source velocity are shown graphically for two different cases. In the first case, a thermal shock free surface is considered subjected to traction and in the second case the surface is under the influence of time dependent thermal shock. Finally, some comparisons of the results for different time and moving heat source velocity are presented. In presence of moving heat source all the thermophysical quantities have a great significant effect in all the distributions

Important paradigms of the thermoelastic waves

This paper is devoted to the investigation of the propagation of magneto-thermo-elastic waves in a rotating monoclinic system. The system is electrically conducting in the presence of an applied magnetic field. A general dispersion relation is obtained for magneto-thermo-elastic waves. The propagation of wave produced two elastic waves and two thermal waves. It is found that the elastic waves depend on the applied magnetic field and the rotational frequency, where the thermal waves are independent of these effects. The numerical simulations are presented in this article to support the findings

Plane wave propagation in a 3D anisotropic half-space under Green-Naghdi theory II

In this paper, the theory of coupled thermoelasticity in three dimension is employed for triclinic half-space, subjected to time dependent heat source on the boundary of the space which is traction free and is considered in the context of Green-Naghdi model of type II (thermoelasticity without energy dissipation) of generalized thermoelasticity. Normal mode analysis is used to the non-dimensional coupled equations. Finally, the resulting equations are written in the form of a vector-matrix differential equation which is then solved by eigenvalue approach. Numerical results for the temperature, thermal stresses, and displacements are presented graphically and analyzed. Mathematical results shown in thermoelastic curves were supplemented by tectonic movements of elastic lithospheric plates

Generalized thermo-visco-elastic problem of a spherical shell with three-phase-lag effect

AbstractThis problem deals with the thermo-visco-elastic interaction due to step input of temperature on the stress free boundaries of a homogeneous visco-elastic isotropic spherical shell in the context of generalized theories of thermo-elasticity. Using the Laplace transformation the fundamental equations have been expressed in the form of vector–matrix differential equation which is then solved by eigen value approach. The inverse of the transformed solution is carried out by applying a method of Bellman et al. [R. Bellman, R.E. Kolaba, J.A. Lockette, Numerical Inversion of the Laplace Transform, American Elsevier Publishing Company, New York, 1966]. The stresses are computed numerically and presented graphically in a number of figures for copper material. A comparison of the results for different theories (TEWED (GN-III), three-phase-lag method) is presented. When the body is elastic and the outer radius of the shell tends to infinity, the corresponding results agree with the result of existing literature

Magnetoelastic plane waves in rotating media in thermoelasticity of type II (G-N model)

A study is made of the propagation of time-harmonic plane waves in an infinite, conducting, thermoelastic solid permeated by a uniform primary external magnetic field when the entire medium is rotating with a uniform angular velocity. The thermoelasticity theory of type II (G-N model) (1993) is used to study the propagation of waves. A more general dispersion equation is derived to determine the effects of rotation, thermal parameters, characteristic of the medium, and the external magnetic field. If the primary magnetic field has a transverse component, it is observed that the longitudinal and transverse motions are linked together. For low frequency (χ≪1, χ being the ratio of the wave frequency to some standard frequency ω∗), the rotation and the thermal field have no effect on the phase velocity to the first order of χ and then this corresponds to only one slow wave influenced by the electromagnetic field only. But to the second order of χ, the phase velocity, attenuation coefficient, and the specific energy loss are affected by rotation and depend on the thermal parameters cT, cT being the nondimensional thermal wave speed of G-N theory, and the thermoelastic coupling εT, the electromagnetic parameters εH, and the transverse magnetic field RH. Also for large frequency, rotation and thermal field have no effect on the phase velocity, which is independent of primary magnetic field to the first order of (1/χ) (χ≫1), and the specific energy loss is a constant, independent of any field parameter. However, to the second order of (1/χ), rotation does exert influence on both the phase velocity and the attenuation factor, and the specific energy loss is affected by rotation and depends on the thermal parameters cT and εT, electromagnetic parameter εH, and the transverse magnetic field RH, whereas the specific energy loss is independent of any field parameters to the first order of (1/χ)

Pulsed Laser Heating of a Thermoelastic Medium with Two-temperature under Three-phase-lag Model

In this paper, the problem of the generalized thermoelastic medium for three different theories under the effect of a laser pulse and two-temperature is investigated. The Lord–Shulman (L-S), Green-Naghdi of type III (G-N III) and three-phase-lag (3PHL) theories are discussed with two-temperature. The normal mode analysis is used to obtain the analytical expressions of the displacement components, force stress, thermodynamic temperature and conductive temperature. The numerical results are given and presented graphically and the thermal force was applied. Comparisons are made with the results predicted by (3PHL), (G-N III) and (L-S) in the presence and absence of two-temperature. The boundary plane surface is heated by a non-Gaussian laser beam

Thermomagnetic behavior of a semiconductor material heated by pulsed excitation based on the fourth-order MGT photothermal model

This article proposes a photothermal model to reveal the thermo-magneto-mechanical properties of semiconductor materials, including coupled diffusion equations for thermal conductivity, elasticity, and excess carrier density. The proposed model is developed to account for the optical heating that occurs through the semiconductor medium. The Moore–Gibson–Thompson (MGT) equation of the fourth-order serves as the theoretical framework to establish the photothermal model. It is well-known that the optical and heat transfer properties of such materials behave as random functions of photoexcited-carrier density; therefore, the current model is remarkably more reliable compared to the earlier closed-form theories which are limited to a single form. The constructed theoretical framework is able to investigate the magneto-photo-thermoelastic problems in a semiconductor medium due to laser pulse excitation as a case study. Some parametric studies are used to exhibit the impact of thermal parameters, electromagnetic fields, laser pulses and thermoelectric coupling factors on the thermomagnetic behavior of physical variables. Finally, several numerical examples have been presented to draw the distributions of the examined field variables

Viscothermoelastic waves in a gravitated piezoelectric multilayered LEMV /CFRP cylinder coated with thin film

The present paper is concerned the effects of gravitational force and rotation in a composite multilayered hollowcylinder which contain inner and outer piezo-thermoelasticity layers bonded by Linear Elastic Material with Voids (LEMV) withinthe frame of dual-phase-lag model.Also the composite multilayered hollow cylinder coated with thin film is considered.Theequation of displacement components, temperature, and electric are obtained using linear theory of elasticity. The dispersionequations are acquired by means of traction free boundary conditions and are numerically analyzed for CdSe material.Theenumerated frequency, thermal and electrical nature against wave number in the presence of gravatity and rotation is presentedgraphically. Adhesive layer LEMV is compared with Carbon Fiber Reinforced Polymer (CFRP) in presence of gravity androtation