Nantu Sarkar

Bio: Nantu Sarkar is an academic researcher from University of Calcutta. The author has contributed to research in topics: Thermoelastic damping & Isotropy. The author has an hindex of 16, co-authored 58 publications receiving 780 citations. Previous affiliations of Nantu Sarkar include University of Burdwan & Jadavpur University.

Modified Green–Lindsay model on the reflection and propagation of thermoelastic plane waves at an isothermal stress-free surface

Abstract: The present study is concerned with the reflection and propagation of thermoelastic harmonic plane waves from the stress-free and isothermal surface of a homogeneous, isotropic thermally conducting elastic half-space in the frame of the modified Green–Lindasy (MGL) theory of generalized thermoelasticity with strain rate proposed by Yu et al (Meccanica 53:2543–2554, 2018) The thermoelastic coupling effect creates two types of coupled longitudinal waves which are dispersive as well as exhibit attenuation Different from the thermoelastic coupling effect, there also exists one independent vertically shear-type (SV-type) wave In contrast to the classical Green–Lindsay (GL) and Lord–Shulman (LS) theories of generalized thermoelasticity, the SV-type wave is not only dispersive in nature but also experiences attenuation Analytical expressions for the amplitude ratios of the reflected thermoelastic waves are determined when a coupled longitudinal wave is made incident on the free surface The paper concludes with the numerical results on the phase speeds and the amplitude ratios for specific parameter choices Various graphs have been plotted to analyze the behavior of these quantities The characteristics of employing the MGL model are discussed by comparing the numerical results obtained for the present model with those obtained in case of the GL and LS models

Vibrations of a nonlocal thermoelastic cylinder with void

Abstract: The present work is devoted to the investigation of the free vibrations of a homogeneous isotropic nonlocal thermoelastic cylinder with void. Time-harmonic variations are used to reduce the governing partial differential equations to a system of ordinary differential equations. The frequency equation for the continuation of vibrations for the mode numbers in the considered cylinder is deduced in closed form for traction-free and isothermal/thermally insulated boundary conditions. To observe the free vibration, the frequency equation is further studied by using the numerical iteration method with the help of MATLAB software. The numerically simulated results from the analytical solutions are shown graphically for the natural frequency, thermoelastic damping and the frequency shift against mode numbers for the nonlocal as well as the local thermoelastic cylinders in the presence and absence of the void.

Analysis of Magnetothermoelastic Response in a Fiber-Reinforced Elastic Solid Due to Hydrostatic Initial Stress and Gravity Field

Abstract: The aim of the present paper is to investigate the influences of the hydrostatic initial stress and the gravity field on the plane waves in a fiber-reinforced magnetothermoelastic isotropic medium using the Lord–Shulman model of generalized thermoelasticity with one relaxation time. The problem has been solved numerically using the normal mode analysis together with the eigenvalue approach. Numerical results for temperature, the displacement components, and the stresses are represented graphically, and the results are analyzed. The graphical results indicate that the effects of the hydrostatic initial stress, gravity field, and the magnetic field on plane waves in the fiber-reinforced thermoelastic medium are very pronounced. Comparisons are made to results in the absence of the hydrostatic initial stress, gravity field, and the magnetic field. Such problems are very important in many dynamical systems.

Temperature rate dependent generalized thermoelasticity with modified ohm's law

Abstract: The present work is concerned with an electro-magneto-thermoelastic coupled problem for a homogeneous, isotropic, thermally and electrically conducting semi-infinite solid medium in two-dimensional space where an initial magnetic field with constant intensity acts parallel to the plane boundary of the half-space. The surface of the half-space taking as traction free which is subjected to a thermal shock. The modified Ohm's law including the temperature gradient and charge density effect to the governing equations of the generalized thermoelasticity under the temperature rate dependent thermoelasticity (TRDTE) proposed by Green and Lindsay (GL model) has been introduced. Normal mode analysis together with eigenvalue approach technique is used to obtain the general solutions for the physical quantities. Numerical results for the physical quantities are illustrated graphically and analyzed. The graphical results indicate that the effect of the coefficient connecting the temperature gradient and the electric current density of the modified Ohm's law on the plane waves is very pronounced. Comparison are made with the results obtained in the absence of the above coefficient.

Extended Irreversible Thermodynamics

Abstract: 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

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

Abstract: 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...

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

Abstract: 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.

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

Abstract: 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...

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

Abstract: 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.