Thermoelastic Interactions Research Articles

State–space approach on two-temperature three-phase-lag thermoelastic medium with a spherical cavity due to memory-dependent derivative

In this article, thermoelastic interaction in a two-temperature generalized thermoelastic unbounded isotropic medium having spherical cavity has been studied in the context of memory-dependent derivative (MDD). The governing coupled equations for the problem associated with kernel function and time delays are considered in the perspective of two-temperature (2 T) three-phase-lag thermoelasticity theory. The bounding surface of the spherical cavity is subjected to mechanical and thermal loading. Using Laplace transform, the problem is transformed from the space–time domain and then solved by the state–space approach method. Suitable numerical technique is used to find the inversion of Laplace transforms. Comparisons are made graphically, between the 2 T three-phase-lag model and 2 T Lord Shulman model with MDD. Also, the effects of time-delay parameter and the kernel function on the distributions of the strain component, thermodynamic temperature, conductive temperature, displacement components, radial and hoop stresses are examined and illustrated graphically. The results show that due to the influence of the three-phase-lag-effect, memory effect, two-temperature parameter, the kernel function and time-delay, all the distributions are affected extensively.

Thermoelastic interactions in a functionally graded material with gravity and rotation under dual-phase-lag heat conduction

Present work is aimed to study the solution of a problem on thermoelastic interactions in a functionally graded material under dual-phase-lag model in the presence of rotation and gravity. By employing the normal mode technique, the analytical expressions for the displacement components, stresses and temperature field are obtained in the physical domain. These expressions are also calculated numerically and represented graphically in the presence and absence of gravity and rotation. Discussions have been made to highlight the effects of non-homogeneity, rotation and gravity on these physical fields. Moreover, the significant differences in the numerical results for three models known as dual-phase-lag (DPL) model, Lord–Shulman (L–S) model, and coupled thermoelastic (C-T) model are also observed for two different times. Some particular cases of interest have been inferred from the present study. Although various investigations do exist to observe the disturbances in a thermoelastic medium under the effects of different parameters, the work in its present form i.e., thermally induced vibrations in a non-homogeneous thermoelastic material with rotation and gravity under DPL model has not been studied till now.

Quasi-adiabatic approximation for thermoelastic surface waves in orthorhombic solids

An asymptotic model for time-harmonic motion in fully-coupled linear thermoelastic orthorhombic materials is presented. The asymptotic approach takes advantage of the observation that the parameter expressing departure from the purely adiabatic regime is extremely small in practice. Consequently, the leading order bulk response turns out to be non-dissipative, and is governed by the usual equations of elastodynamics with adiabatic material constants. In the case of isothermal stress-free boundary conditions, it is shown that thermoelastic interaction is dominated by a thermoelastic boundary layer. Hence, effective boundary conditions may be constructed, which duly account for the influence of this boundary layer and successfully describe dispersion and dissipation of surface waves to leading order. As an illustration, in the special case of an isotropic half-space with free isothermal boundary conditions, we recover the asymptotic results by Chadwick and Windle (1964). Numerical comparison of the dispersion curves for surface waves in an orthorhombic half-space shows excellent agreement between the exact fully-coupled thermoelastic problem and the corresponding quasi-adiabatic approximation, even for relatively large wavenumbers.

Relaxation effects on thermoelastic interactions for time-dependent moving heat source under a recent model of thermoelasticity

In the present article, we investigate the thermal and elastic behaviour of an infinite thermoelastic material with a cylindrical cavity caused by a time-dependent moving heat source. The cavity surface is assumed to be subjected to a thermal shock. The formulation of the problem is applied for the recently proposed generalized thermoelastic model [Modified Green–Lindsay (MGL)] that takes into account the strain and temperature rates in the constitutive relations. We derive the governing equations in the present context along with the other two models, namely Lord–Shulman model and Green–Lindsay, by unifying governing equations under all these three models. The solutions are obtained for all three models in the Laplace transform domain, which are represented by unified expressions. The numerical computations for temperature, displacement and thermal stresses are carried out and depicted graphically. A detailed comparison is made amongst the results predicted by three models to highlight the effects of velocity of heat source and strain, temperature rate terms involved in the MGL model.

Field equations and memory effects in a functionally graded magneto-thermoelastic rod

The main concern of this article is to deal with the thermoelastic interaction in a functionally graded thermoelastic rod being enlightened by the memory-dependent derivative. This article investigates the transient phenomena due to the influence of an induced magnetic field of constant intensity and due to the presence of a moving heat source of constant velocity in the context of three-phase lag model of generalized thermoelasticity. Employing the Laplace and the Fourier transforms as tool, the problem has been constructed in the transformed domain. The inversions of the Fourier transform have been carried out using residual calculus whereas the numerical inversions of the Laplace transform have been performed employing the Riemann sum approximation method. Numerical computations for stress, displacement, and temperature within the rod are carried out and have been demonstrated graphically. The results also demonstrate how the nonhomogeneity parameter and the speed of the moving heat source influence the thermophysical quantities. It is observed that the temperature, thermally induced displacement, and stress of the rod are found to decrease at large source speed. Also, significant differences on the thermophysical quantities are revealed due to the influence of magnetic field, nonhomogeneity, and memory effect also.

A study on thermo-elastic interactions in 2D porous media with-without energy dissipation

The generalized thermoelastic analysis problem of a two-dimension porous medium with and without energy dissipation are obtained in the context of Green–Naghdi's (GNIII) model. The exact solutions are presented to obtain the studying fields due to the pulse heat flux that decay exponentially in the surface of porous media. By using Laplace and Fourier transform with the eigenvalues scheme, the physical quantities are analytically presented. The surface is shocked by thermal (pulse heat flux problems) and applying the traction free on its outer surfaces (mechanical boundary) through transport (diffusion) process of temperature to observe the analytical complete expression of the main physical fields. The change in volume fraction field, the variations of the displacement components, temperature and the components of stress are graphically presented. Suitable discussion and conclusions are presented.

Generalized thermo-elastic interaction in a fiber-reinforcedmaterial with spherical holes

In this paper, a mathematical model is used to the evaluation of thermoelastic interactions in fiber-reinforced material with a spherical cavity. With the goal of establishing the generalized thermoelastic model with thermal relaxation time are exploited. inner surface of the spherical cavity is tractions free and loaded by the uniform step in temperature. The finite element scheme is used to get the problem numerical solutions. The numerical results have been discussed graphically to show the impacts of the presence and the absence of reinforcement.

Weak solution to the incompressible viscous fluid and a thermoelastic plate interaction problem in 3D

In this paper we deal with a nonlinear interaction problem between an incompressible viscous fluid and a nonlinear thermoelastic plate. The nonlinearity in the plate equation corresponds to nonlinear elastic force in various physically relevant semilinear and quasilinear plate models. We prove the existence of a weak solution for this problem by constructing a hybrid approximation scheme that, via operator splitting, decouples the system into two sub-problems, one piece-wise stationary for the fluid and one time-continuous and in a finite basis for the structure. To prove the convergence of the approximate quasilinear elastic force, we develop a compensated compactness method that relies on the maximal monotonicity property of this nonlinear function.

Response of thermoelastic cylindrical cavity in a non-local infinite medium due to a varying heat source

The current paper is concerned with a new size-dependent thermoelastic model where the constitutive and the motion equations are modified. The governing equations of the introduced model are derived based on the generalized dual-phase-lag thermoelastic model and non-local elasticity theory. Additionally, the present work is an attempt to investigate a thermoelastic interaction in an infinite medium with a cylindrical cavity based on the proposed model. The cavity surface is traction free and exposed to a time-dependent moving heat source. The analytical formulas for the field quantities are obtained first in the Laplace transform domain. To find the inverse Laplace transform into the physical quantities, a numerical technique is performed. The numerical results are discussed in different cases to highlight the effect of the size -scale parameter and the speed of the heat source on the studied thermo-physical fields.

Thermoelastic interactions in an unbounded solid due to a continuous heat source using the modified TPL G–N model

This article exhibits the thermoelastic interactions because of a consistent heat source in an isotropic, homogeneous, unbounded elastic solid with regards to the modified theory of thermoelasticity without energy dissipation. A novel modification for the three-phase-lag Green–Naghdi (TPL G–N) heat conduction equation is proposed for this purpose. A new potential function is employed to help in solving the present problem together with Laplace and Hankel transforms. After inverting Laplace transforms, the small-time approximated solutions are used to obtain expository expressions for the field variables inside the medium. The trend of variations in all quantities past the elastic wavefront to the heat wavefront is investigated. The quantities suddenly bounce to a high worth just previously the situation of the heat wavefront and from that point hop again to zero qualities.

Electro–magneto–thermoelastic interactions in initially stressed orthotropic medium with Green–Naghdi model type-III

This article is concerned with a study of electro–magneto–thermoelastic interactions under Green–Naghdi theory-III of generalized thermoelasticity in the presence of initial stress. The fundamental equations of the two-dimensional problem in orthotropic medium under the influence of electric and magnetic field are obtained in the form of a vector–matrix of differential equation by employing normal mode analysis which is then solved by eigenfunction expansion method. The solution for temperature distribution, displacements, and stress components is obtained. The effect of magnetic field, electric field and phase velocity on the considered parameters is observed in the figures.

Thermoelastic fractional derivative model for exciting viscoelastic microbeam resting on Winkler foundation

In the current investigation, the thermoelastic vibration of a viscoelastic microbeam resting on the Winkler foundation is studied using the fractional-order theory. To describe the damping of the viscoelastic material according to experimental results, the Kelvin–Voigt model is replaced by a new form with a fractional-order derivative. The generalized thermoelasticity model and Euler–Bernoulli beam theory are used to construct the governing equation. The microbeam is subjected to axial load, ultrafast laser heating, and varying sinusoidal heat. The governing equation is then solved using the Laplace transform technique to determine the deflection and thermoelastic interaction responses of microbeams. The effects of many parameters such as the coefficient of viscosity, axial load, fractional derivative order, laser pulse duration, and foundation parameter on the microbeam response are explained and discussed in detail.

A generalized heat conduction model of higher-order time derivatives and three-phase-lags for non-simple thermoelastic materials

In the current work, a new generalized model of heat conduction has been constructed taking into account the influence of the microscopic structure into the on non-simple thermoelastic materials. The new model was established on the basis of the system of equations that includes three-phase lags of higher-order and two different temperatures, namely thermodynamic and conductive temperature. The two-temperature thermoelastic model presented by Chen and Gurtin (Z Angew Math Phys 19(4):614–627, 1968) and some other previous models have been introduced as special cases from the proposed model. As an application of the new model, we studied the thermoelastic interactions resulting from sudden heating in an isotropic solid subjected to external body force. The influence of the discrepancy parameter and higher-order of the time-derivative has been discussed. This work will enable future investigators to gain insight into non-simple thermoelasticity with different phase delays of higher-order in detail.

A Study on Thermoelastic Interaction in a Poroelastic Medium with and without Energy Dissipation

In the current work, a new generalized model of heat conduction has been constructed taking into account the influence of porosity on a poro-thermoelastic medium using the finite element method (FEM). The governing equations are presented in the context of the Green and Naghdi (G-N) type III theory with and without energy dissipations. The finite element scheme has been adopted to present the solutions due to the complex formulations of this problem. The effects of porosity on poro-thermoelastic material are investigated. The numerical results for stresses, temperatures, and displacements for the solid and the fluid are graphically presented. This work provides future investigators with insight regarding details of non-simple poro-thermoelasticity with different phases.

Effects of nonlocal thermoelasticity on nanoscale beams based on couple stress theory

A modified nonlocal Bernoulli–Euler model was established in this paper to analyze thermoelastic interactions in isotropic nanobeams subjected to ramp‐type heating, depending on the modified couple stress and generalized thermoelasticity theories. To solve this problem, the thermoelasticity theory with one thermal relaxation time (Lord–Shulman [LS]) is proposed. Due to the modified couple stress, the analytical expressions for deflection, temperature, flexure moment, and displacement in the nanobeam were obtained by using the Laplace transform technique. In addition, comparisons were shown in graphs to estimate the effects of the various parameters such as the couple stress, and the ramping time parameter on all the fields studied under consideration. Also, the numerical results are provided to demonstrate the small‐scale impact on the resonator of the nanobeams.

Fractional order theory of Cattaneo-type thermoelasticity using new fractional derivatives

Transient thermoelastic interactions between materials and the moving heat sources, i.e. Laser additive manufacturing, Laser-assisted thermotherapy, high speed sliding and rolling contacts, are becoming increasingly important. In this work, a unified fractional thermoelastic theory is developed, and applied to study transient responses caused by a moving heat source. Theoretically, new insights on fractional thermoelasticity are provided by introducing new definitions of fractional derivative, i.e. Caputo-Fabrizio, Atangana–Baleanu and Tempered-Caputo type. Numerically, a semi-infinite medium subjected to a source of heat moving with constant velocity is considered within the present model under two different sets of boundary conditions: stress free and temperature given for the first, displacement fixed and thermally adiabatic for the second. Analytical solutions to all responses are firstly formulated in Laplace domain, and then transformed into time domain through numerical method. The numerical results show that Caputo-Fabrizio and Atangana–Baleanu type models predict smaller transient responses than Caputo type theory, while Tempered-Caputo model may give larger results by increasing the tempered parameter. Meanwhile, the effect of fractional order, tempered parameter of Tempered-Caputo model, and the velocity of heat source on all responses is discussed in detail. The time history of responses shows that: for long-term process, the exponential function of TC definition will make sense, and the temperature from TC model is greatly different from that of C model. This work may provide comprehensive understanding for thermoelastic interactions due to moving heat source, and open up possibly wide applications of such new fractional derivatives.

Generalized Thermoelastic Interactions in a Poroelastic Material Without Energy Dissipations

The purpose of this investigation is providing a method to study the effect of porosity in a porothermoelastic medium by the finite element technique. The formulations are applied under Green-Naghdi model without energy dissipations. One-dimensional application for a poroelastic half-space is considered. Due to the complex basic equations, the finite element method (FEM) has been adopted to solve this problem. The numerical outcomes for displacements, temperatures and the stress components are represented graphically for the solid and the fluid.

A thermodynamic analysis of an enhanced theory of heat conduction model: Extended influence of finite strain and heat flux

An Eulerian form of thermodynamically consistent generalized thermoelastic model capable of accounting for thermal signals is proposed. The heat flux is assumed to consist of both energetic and dissipative components. The constitutive relations for the stress, entropy and the heat fluxes are derived in the spatial coordinate system. Later on, a domain of dependence inequality for the proposed hyperbolic type heat conduction model is proved. The linearised form of this improved thermoelasticity theory of finite deformation is employed to study the thermoelastic interactions due a continuous source of heat in isotropic elastic solids. This newly developed model is also applied in a thermoelastic saturated porous medium. In order to obtain the exact analytical expressions of the field functions, appropriate integral transformations are employed in a convenient way.

A novel model of nonlocal thermoelasticity with time derivatives of higher order

The objective of this work is to introduce a new system of differential equations describing the nonlocal thermoelasticity theory with higher time derivatives and two‐phase lags. In order to obtain this model, we used the nonlocal continuum theory proposed by Eringen and the methodology of the Taylor series expansion of higher‐order time derivatives. Some generalized thermoelasticity theories follow as limited cases. This model is used to study the thermoelastic interaction in a nonlocal medium. The medium is exposed to an applied magnetic field and a periodic time heat source with a constant strength. Some comparisons have been displayed in figures to estimate the influences of the nonlocal parameter and magnetic field as well as the parameters of higher‐order on all the field quantities.

Three-phase lag model of thermo-elastic interaction in a 2D porous material due to pulse heat flux

Purpose The purposes of this study, a generalized model for thermoelastic wave under three-phase lag (TPL) model is used to compute the increment of temperature, the components of displacement, the changes in volume fraction field and the stress components in a two-dimension porous medium. Design/methodology/approach By using Laplace-Fourier transformations with the eigen values methodologies, the analytical solutions of all physical variables are obtained. Findings The derived methods are estimated with numerical outcomes which are applied to the porous media in simplified geometry. Originality/value Finally, the outcomes are represented graphically to display the difference among the models of the TPL and the Green and Naghdi (GNIII) with and without energy dissipations.