Der vorliegende Band enthált sechs Beitrage, in denen punktuell und exemplarisch der Stand der Forschung beleuchtet wird. Ein Beitrag von Codling und Frasinski beschreibt in erster Linie Experimente zum noch wenig verstandenen Phânomen der dissoziativen Ionisation von Molekülen, bei dem diese in einem intensiven Laserfeld mehrere Elektronén verlieren und in Ionen mit hoher kinetischer Energie zerfallen. Ein wesentlicher Teil dieses Beitrags widmet sich einer von den Autoren entwickelten Auswertungstechnik, welche die Korrelationen zwischen den Fiugzeiten emittierter Ionen und Elektronén sichtbar macht. Es folgen drei Beitrage zur Théorie. Schmelcher und Cederbaum beschreiben Effekte starker statischer Felder, die nur dann zu verstehen sind, wenn die Nicht-Separation der Schwerpunktsbewegung im auBeren Magnetfeld korrekt beriicksichtigt wird. Dies fiihrt

Extended Irreversible Thermodynamics

A new nonlocal theory of generalized thermoelastic materials with voids based on Eringen’s nonlocal elasticity and Caputo fractional derivative is established. The one-dimensional form of the above...

Nonlocal theory of thermoelastic materials with voids and fractional derivative heat transfer

A three-dimensional model of the generalized thermoelasticity without energy dissipation under temperature-dependent mechanical properties is established. The modulus of elasticity is taken as a linear function of the reference temperature. The resulting formulation in the context of Green and Naghdi model II is applied to a half-space subjected to a time-dependent heat source and traction free surface. The normal mode analysis and eigenvalue approach techniques are used to solve the resulting non-dimensional coupled equations. Numerical results for the field quantities are given in the physical domain and illustrated graphically. The results are also compared to results obtained in the case of temperature-independent modulus of elasticity.

Eigenvalue approach in a three-dimensional generalized thermoelastic interactions with temperature-dependent material properties

This article highlights on the study of coupled plasma, thermal and elastic waves within an orthotropic infinite semiconducting medium in context of photothermal transport process having a spherica...

Photo-thermo-elastic wave propagation in an orthotropic semiconductor with a spherical cavity and memory responses

The purpose of this study is to provide a method to investigate the effects of thermal relaxation times in a poroelastic material by using the finite element method. The formulations are applied under the Green and Lindsay model, with four thermal relaxation times. Due to the complex governing equation, the finite element method has been used to solve these problems. All physical quantities are presented as symmetric and asymmetric tensors. The effects of thermal relaxation times and porosity in a poro-thermoelastic medium are studied. Numerical computations for temperatures, displacements and stresses for the liquid and the solid are presented graphically.

https://www.mdpi.com/2073-8994/12/3/488/pdf

A GL Model on Thermo-Elastic Interaction in a Poroelastic Material Using Finite Element Method

The aim of the present work is to investigate the influence of the gravity field on the plane waves in a linearly fiber-reinforced magneto-thermoelastic isotropic medium in the context of the two-temperature theory of generalized thermoelasticity under Lord-Shulman model. The problem has been solved numerically using the normal mode analysis together with the eigenvalue approach. Numerical results for the conductive temperature, thermodynamic temperature, displacement components and the stresses are represented graphically and the results are analyzed. The graphical results indicate that the effect of the two-temperature parameter, gravity field and the magnetic field on the plane waves in the fiber-reinforced thermoelastic medium are very pronounced. Comparisons are made with the results in the presence and absence of the two-temperature parameter, gravity field and the magnetic field. Such problems are very important in many dynamical systems.

The Effect of Gravity Field on the Plane Waves in a Fiber-Reinforced Two-Temperature Magneto-Thermoelastic Medium Under Lord-Shulman Theory

Recently, Sherief et al. (Int. J. Solids Struct. 47:269–275, 2010) proposed a model in generalized thermoelasticity based on the fractional order time derivatives. The propagation of electro-magneto-thermoelastic disturbances in a perfectly conducting elastic half-space is investigated in the context of the above fractional order theory of generalized thermoelasticity. There acts an initial magnetic field parallel to the plane boundary of the half-space. Normal mode analysis together with the eigenvalue approach technique is used to solve the resulting non-dimensional coupled governing equations of the problem. The obtained solution is then applied to two specific problems for the half-space, whose boundary is subjected to (i) thermally isolated surfaces subjected to time-dependent compression and (ii) a time-dependent thermal shock and zero stress. The effects of fractional parameter and magnetic field on the variations of different field quantities inside the half-space are analyzed graphically.

The effect of fractional parameter on a perfect conducting elastic half-space in generalized magneto-thermoelasticity

In ["Theory of fractional order generalized thermoelasticity," Journal of Heat Transfer132, 2010] Youssef has proposed a model in generalized thermoelasticity based on the fractional order time derivatives. The current manuscript is concerned with a two-dimensional generalized thermoelastic coupled problem for a homogeneous isotropic and thermally conducting thermoelastic rotating medium in the context of the above fractional order generalized thermoelasticity with two relaxation time parameters. The normal mode analysis technique is used to solve the resulting non-dimensional coupled governing equations of the problem. The resulting solution is then applied to two concrete problems. The effect of the fractional parameter and the time instant on the variations of different field quantities inside the elastic medium are analyzed graphically in the presence of rotation.

Effect of fractional parameter on plane waves in a rotating elastic medium under fractional order generalized thermoelasticity

This paper aims to study the effect of the elastic nonlocality on the transient waves in a two-dimensional thermoelastic medium influenced by thermal loading due to the laser pulse. The bounding plane surface is heated by a non-Gaussian laser beam. The problem is discussed under the Eringen\'s nonlocal elasticity model and the Green-Naghdi (G-N) theory with and without energy dissipation. The normal mode analysis method is used to get the exact expressions for the physical quantities which illustrated graphically by comparison and discussion. The effects of nonlocality and different values of time on the displacement, the stresses, and the temperature were made numerically. All the computed results obtained have been depicted graphically and explained.

Effect of the laser pulse on transient waves in a non-local thermoelastic medium under Green-Naghdi theory

The vibration of a functionally graded axisymmetric nonlocal thermoelastic hollow sphere with dual-phase-lag effect is addressed in this paper. Surfaces of the sphere are assumed to be thermally insulated or isothermal and stress free. According to a simple power law, the material is assumed to be graded in the radial direction. The linear theory of modified thermoelasticity with a dual phase lag based on Eringen’s nonlocal elasticity is employed to model this problem. The Matrix Frobenius method of continued power series is introduced to derive the analytical solutions. The phase velocity relations for the existence of various modes of vibrations in the designed hollow sphere are derived in compact forms. In order to explore the attributes of vibrations, the fixed-point numerical iteration technique is used to solve the secular equations. The numerical computations for the material crust in respect of the natural frequencies, thermoelastic damping and the frequency shifting are presented graphically using MATLAB software tools.

Nantu Sarkar

Papers

The Effect of Gravity Field on the Plane Waves in a Fiber-Reinforced Two-Temperature Magneto-Thermoelastic Medium Under Lord-Shulman Theory

The effect of fractional parameter on a perfect conducting elastic half-space in generalized magneto-thermoelasticity

Effect of fractional parameter on plane waves in a rotating elastic medium under fractional order generalized thermoelasticity

Effect of the laser pulse on transient waves in a non-local thermoelastic medium under Green-Naghdi theory

Vibration analysis of functionally graded thermoelastic nonlocal sphere with dual-phase-lag effect