Showing papers in "Journal of Thermal Stresses in 2015"
TL;DR: In this paper, a thermomechanical vibration analysis of functionally graded (FG) nanobeams subjected to in-plane thermal loads is carried out by presenting a Navier-type solution and employing a semi-analytical differential transform method (DTM) for the first time.
Abstract: In this study, thermomechanical vibration analysis of functionally graded (FG) nanobeams subjected to in-plane thermal loads are carried out by presenting a Navier-type solution and employing a semi-analytical differential transform method (DTM) for the first time. Two types of thermal loading, namely, linear and non-linear temperature rises through the thickness direction are considered. Thermomechanical properties of FG nanobeam are supposed to vary smoothly and continuously throughout the thickness based on power-law model and material properties are assumed to be temperature-dependent. Eringen non-local elasticity theory is exploited to describe the size dependency of FG nanobeam. Using Hamilton's principle, the non-local equations of motion together with corresponding boundary conditions are obtained for the free vibration analysis of FG nanobeams including size effect and they are solved applying DTM. According to numerical results, it was revealed that the proposed modeling and semi-analytical appr...
74 citations
TL;DR: In this paper, the dynamic characteristics of a double-FGM viscoelastic nanoplates-system subjected to temperature change with considering surface effects (surface elasticity, tension and density) is studied.
Abstract: In this article, based on the nonlocal elasticity theory of Eringen, dynamic characteristics of a double-FGM viscoelastic nanoplates-system subjected to temperature change with considering surface effects (surface elasticity, tension and density) is studied. Two Kirchhoff nanoplates are coupled by an internal Kelvin–Voigt viscoelastic medium and also are limited to the external Pasternak elastic foundation. The material properties of the simply supported functionally graded nanoplates are assumed to follow power law distribution in the thickness direction. The governing equations of motion for three cases (out-of-phase vibration, in-phase vibration and one nanoplate fixed) are derived from Hamilton's principle. The analytical approach is employed to determine explicit closed-form expression for complex natural frequencies of the system. Numerical results are presented to show variations of the frequency of double-FGM viscoelastic nanoplates corresponding to various values of the nonlocal parameter, temper...
62 citations
TL;DR: In this paper, the authors studied the two-dimensional problem of a crack in thermoelectric materials and derived the general solution based on the complex variable method, which is obtained in closed-form for a crack subjected to remote electric current and heat flow.
Abstract: The two-dimensional problem of a crack in thermoelectric materials is studied in this research. The general solution is derived based on the complex variable method. For the case of a crack subjected to remote electric current and heat flow, the solutions are obtained in closed-form. The results show that the fields of heat flow, electric current, and stress exhibit traditional square-root singularity at the crack tip. The remote electric current produces both type I and II stress intensity factor. Furthermore, the stress intensity factor has a linear relationship with the heat flux, but a non-linear relationship with the electric current.
58 citations
TL;DR: In this paper, a normal mode method is proposed to analyze the problem and obtain numerical solutions for the displacement components, stresses, temperature distribution and change in the volume fraction field in the dual phase lag model.
Abstract: The aim of the present study is concerned with the thermal loading due to laser pulse on thermoelastic medium with voids in the dual phase lag model (DPL). The material is a homogeneous isotropic elastic half-space and heated by a non-Gaussian laser beam with pulse duration of 8 ps. A normal mode method is proposed to analyze the problem and obtain numerical solutions for the displacement components, stresses, temperature distribution and change in the volume fraction field. The results of the physical quantities have been illustrated graphically by comparison between (DPL) and Lord-Schulman (L–S) theory for two values of time and for different values of a phase-lag of heat flux τ q .
46 citations
TL;DR: In this paper, a non-linear mathematical model is developed based on higher-order shear deformation theory by taking Green-Lagrange type of nonlinear kinematics.
Abstract: Non-linear vibration behavior of the laminated composite curved panel of different geometries (cylindrical, elliptical, hyperboloid, paraboloid and flat panel) under thermal environment is investigated in this article A non-linear mathematical model is developed based on higher-order shear deformation theory by taking Green–Lagrange type of non-linear kinematics The governing equation of the vibrated panel is obtained through Hamilton's principle and discretized using the non-linear finite element steps The responses are obtained through direct iterative method and compared with those available in published literature The effect of different parameters on the non-linear vibration behavior of the curved panel has been discussed in detail
38 citations
TL;DR: In this article, an explicit formula of thermoelastic damping has been derived for the two-temperature generalized thermo-elasticity theory in the context of nanobeam resonators.
Abstract: This work is concerned with the study of the thermoelastic damping of nanobeam resonators in the context of the two-temperature generalized thermoelasticity theory. An explicit formula of thermoelastic damping has been derived. Influences of the beam height, the relaxation time parameter, the two-temperature parameter and the isothermal value of frequency have been studied with some comparisons between the Biot model and Lord–Shulman model (L–S). Numerical results show that the values of thermal relaxation parameter and the two-temperature parameter have a strong influence on thermoelastic damping in nanoscales.
37 citations
TL;DR: In this article, an infinitely long solid circular cylinder, whose lateral surface is traction free and subject to a known surrounding temperature, is considered and the inversion process is carried out using a numerical method based on Fourier series expansions.
Abstract: In this study, we consider an infinitely long solid circular cylinder, whose lateral surface is traction free and subject to a known surrounding temperature. The problem is in the context of the fractional order thermoelasticity theory. The medium is assumed to be initially quiescent. The solution is obtained by a direct approach without the customary use of potential functions. Laplace transform technique is used to obtain the general solution for any set of boundary conditions. The inversion process is carried out using a numerical method based on Fourier series expansions. Numerical results are given and represented graphically.
30 citations
TL;DR: In this article, the fractional order theory of thermoelasticity is applied to the two-dimensional problem of a thick plate whose lower and upper surfaces are traction free and subjected to a given axisymmetric temperature distribution.
Abstract: In this work, the fractional order theory of thermoelasticity is applied to the two-dimensional problem of a thick plate whose lower and upper surfaces are traction free and subjected to a given axisymmetric temperature distribution. Laplace and Hankel transform techniques are used to derive the solution in the transformed domain. Numerical results are computed and represented graphically for the temperature, displacement and stress distributions.
28 citations
TL;DR: In this paper, the effect of two temperatures on an axially moving microbeam subjected to ramp-type heating is studied and the generalized thermoelasticity theory with one relaxation time model is used.
Abstract: In this article, the effect of two temperatures on an axially moving microbeam subjected to ramp-type heating is studied. The generalized thermoelasticity theory with one relaxation time model is used. The governing equations are expressed in Laplace transform domain. Based on Fourier series expansion technique, the inversion of Laplace transform is done numerically. Some comparisons have been shown in figures to present the effect of the temperature discrepancy and the transport speed on all the studied field quantities. Additional results across the thickness of the microbeam are presented graphically.
28 citations
TL;DR: In this article, an approximate analytical solution method for thermal stresses in an annular fin with variable thermal conductivity is presented, where homotopy perturbation method (HPM) is employed to estimate the non-dimensional temperature field by solving nonlinear heat conduction equation.
Abstract: An approximate analytical solution method for thermal stresses in an annular fin with variable thermal conductivity is presented. Homotopy perturbation method (HPM) is employed to estimate the non-dimensional temperature field by solving nonlinear heat conduction equation. The closed-form solutions for the thermal stresses are formulated using the classical thermoelasticity theory coupled with HPM solution for temperature field. The plane state of stress conditions are considered in this study. The effects of thermal parameters such as variable thermal conductivity parameter (β), thermogeometric parameter (K), and the non-dimensional coefficient of thermal expansion (χ) on the temperature field and stress field are studied. The results for temperature field and stress field obtained from HPM-based solution are found to be in very close agreement with the results available in literature. Furthermore, the HPM solution is found to be very efficient and handles nonlinear heat transfer equation with greater co...
27 citations
TL;DR: In this paper, a full-scale multi-disc clutch test bench was set up and some sliding experiments were conducted to investigate the temperature evolution processes in low and high lubrication regimes.
Abstract: A full-scale multi-disc clutch test bench was set up and some sliding experiments were conducted to investigate the temperature evolution processes in low and high lubrication regimes. Friction discs with single friction lining were used and arranged back-to-back in order to preserve possible evidences of buckling. Temperatures were measured with thermocouples from four different radii on the mid-plane of the separator disc. Two different kinds of temperature variation processes with obvious critical points of cone shape buckling were obtained. These temperatures can be divided into three effective stages that represent different deformation status of the discs in these experiments. The temperature fields in the contacting separator disc and friction disc were studied through a transient heat conduction model, and the results show that the temperatures measured by the thermocouples from the separator disc can represent the average temperatures in both of the separator disc and friction disc for a long sli...
TL;DR: In this article, a fully analytical solution of the classic coupled thermoelasticity problem in a rotating disk subjected to thermal and mechanical shock loads is presented, where the radial distribution and time history of temperature, displacement and stresses are shown and discussed.
Abstract: A fully analytical solution of the classic coupled thermoelasticity problem in a rotating disk subjected to thermal and mechanical shock loads is presented. Axisymmetric thermal and mechanical boundary conditions are considered in general forms of arbitrary heat transfer and traction, respectively, at the inner and outer radii of the disk. To solve the governing system of equations, an analytical procedure based on the Fourier-Bessel transform is employed. Closed form formulations are presented for temperature and displacement fields. The results of the present formulations are in good agreement with the numerical results available in the literature. The radial distribution and time history of temperature, displacement and stresses are shown and discussed. The propagation of elastic waves and their reflection from the boundary of the disk are clearly shown. In addition, effects of coupling parameter and angular velocity on temperature, displacement and stress fields are investigated.
TL;DR: In this paper, the transient thermal stresses of a functionally graded (FG) cylindrical shell subjected to a thermal shock are investigated by using the Laplace transform and power series method.
Abstract: The transient thermal stresses of a functionally graded (FG) cylindrical shell subjected to a thermal shock are investigated. The dynamic temperature fields of FG shells are obtained by using the Laplace transform and power series method. The differential quadrature method is developed to obtain the transient thermal stresses by solving dynamic governing equations in terms of displacements. The effects of the material constitutions on the transient temperature and the thermal stresses are analyzed in the cases of obverse thermal shock and reverse thermal shock. It turns out that the thermal stresses could be alleviated by means of changing the volume fractions of the constituents.
TL;DR: In this paper, the authors used the principle of virtual work to obtain variationally consistent governing equations and boundary conditions for the simply supported laminated composite plates, and a closed-form solution was obtained using the double trigonometric series technique suggested by Navier.
Abstract: In this article, the thermoelastic bending analysis of laminated composite plates subjected to thermal load linear across the thickness using the four variable refined plate theory is presented. The theory involves four unknown variables, as against five in case of other higher-order theories and first-order shear deformation theory. The theory gives rise to transverse shear stress variation such that the transverse shear stresses vary parabolically across the thickness satisfying shear stress free conditions at top and bottom surfaces of the plate. The theory does not require problem-dependent shear correction factors that are associated with the first-order shear deformation theory. The principle of virtual work is used to obtain variationally consistent governing equations and boundary conditions. The simply supported laminated composite plates are considered for the detail numerical study. A closed-form solution is obtained using the double trigonometric series technique suggested by Navier. The numer...
TL;DR: In this article, the rotation of initially stressed thermoelastic medium with voids subjected to thermal loading due to laser pulse was studied in the context of Green-Naghdi (G-N) theory of types II and III using the normal mode analysis method.
Abstract: This article reports studies on the rotation of initially stressed thermoelastic medium with voids subjected to thermal loading due to laser pulse. The bounding plane surface is heated by a non-Gaussian laser beam. The medium rotated with a uniform angular velocity. The problem was studied in the context of Green-Naghdi (G-N) theory of types II and III using the normal mode analysis method. The comparisons between the both types II and III of (G-N) theory in the presence and the absence of the rotation, the initial stress and for two values of time for considered medium are shown graphically.
TL;DR: In this paper, the authors established the theory of domain of influence for a potential temperature disturbance under the generalized theory of thermoelasticity with three-phase-lag model, and proved that the potential due to the displacement and the temperature fields does not produce any disturbances outside a bounded domain.
Abstract: We establish the theory of domain of influence for a potential-temperature disturbance under the generalized theory of thermoelasticity with three-phase-lag model. For a finite time t > 0, it has been proved that the potential due to the displacement and the temperature fields does not produce any disturbances outside a bounded domain and the domain of influence is dependent on the support of load, the thermoelastic coupling constant and the phase-lag parameters. It has been shown that the domain of influence of the present case reduces to the domain of influence for classical thermoelasticity theory and the thermoelasticity theory with one relaxation parameter.
TL;DR: In this paper, the authors quantify the stresses developed in friction stir welding of mild steel DH36 plates, through an experimental and numerical investigation, and use these models to investigate the evolution of thermal stresses and distortion for different welding parameters.
Abstract: Welding processes involve localized heating which in turn give rise to thermal stresses and distortion. Friction stir welding (FSW) is a solid state joining process where temperatures below melting are experienced. Nonetheless, some degree of thermal heating and consequently thermal stresses develop at the joint. This study aims to quantify the stresses developed in friction stir welding of mild steel DH36 plates, through an experimental and numerical investigation. The temperatures and transient strains developed during FSW, are experimentally measured and used to validate thermo-elastoplastic numerical models. These models are used to investigate the evolution of thermal stresses and distortion for different welding parameters.
TL;DR: In this paper, a generalized thermoelasticity theory with time-delay is constructed, and the uniqueness theorem is proved and variational characterization of the solution is given, for a linear anisotropic and inhomogeneous thermo-elastic solid.
Abstract: A new generalized thermoelasticity theory with time-delay is constructed. The Uniqueness theorem is proved and variational characterization of the solution is given, for a linear anisotropic and inhomogeneous thermoelastic solid. The governing coupled equations of this theory, with a kernel function that can be chosen freely according to the necessity of applications, are applied to one- dimensional problem of a half-space. The bounding surface is taken to be traction free and subjected to a time-dependent thermal shock. The Laplace transforms technique is utilized to obtain the general solution in a closed form. A numerical method is employed for the inversion of the Laplace transforms. According to the numerical results and its graphs, conclusions about the new theory are given. The predictions of the theory are discussed and compared with the dynamic coupled theory.
TL;DR: Two-temperature generalized thermoelasticity theory has been applied to determine the conductive and thermodynamic temperature as well as the deformation and stresses in an annular disk as mentioned in this paper.
Abstract: Two-temperature generalized thermoelasticity theory has been applied to determine the conductive and thermodynamic temperature as well as the deformation and stresses in an annular disk The basic equations have been written in the form of a vector-matrix differential equation in the Laplace transform domain and solved for the field variables in closed form Finally, the time variation and space variation of temperatures, deformation and stresses have been estimated by numerical methods and presented in several graphs and the analysis of the results have been made
TL;DR: In this paper, a model of nonlocal generalized thermoelasticity with one thermal relaxation time is used to consider the vibration behavior of an Euler-Bernoulli (E-B) nanobeam.
Abstract: In this work, a model of nonlocal generalized thermoelasticity with one thermal relaxation time is used to consider the vibration behavior of an Euler-Bernoulli (E-B) nanobeam. The thermal conductivity of the nanobeam is assumed to be temperature-dependent. The nonlocality brings in an internal length scale in the formulation and, thus, allows for the interpretation of size effects. The governing partial differential equations are solved in the Laplace transform domain by adopting the state-space approach of modern control theory. The inverse of Laplace transforms are numerically computed using Fourier expansion techniques. The distributions of the lateral vibration, the temperature, the axial displacement and the bending moment of the nanobeam are determined. The effect of thickness and variability of thermal conductivity, as well as the influence of the nonlocal parameter are investigated.
TL;DR: In this article, the authors investigate the thermoelastic behavior of rotating disks with variable thickness involving a non-uniform heat source, and conduct corresponding simulations, two user subroutines are edited and incorporated into the commercial finite-element code ABAQUS.
Abstract: The research aims to investigate thermoelastic behavior of functionally graded rotating disks with variable thickness involving a non-uniform heat source We assume material properties and thickness of rotating disks to vary in the radial direction Axisymmetric thermal loads including non-uniform heat source, heat flux, and temperature boundary conditions are considered To conduct corresponding simulations, two user subroutines are edited and incorporated into the commercial finite-element code ABAQUS For verification, analytical formulations are derived and solved uniquely by symbolic calculations using the computing software Mathematica The developed finite-element technique is then verified with very good agreement between results by ABAQUS and Mathematica
TL;DR: In this article, the authors analyzed the thermal stresses and crack fields of the Kinta RCC dam at the end of its construction and its service life and showed that there is an increase in the thermal stress after some years of dam completion.
Abstract: Roller compacted concrete (RCC) dams are vulnerable to cracking as a result of high tensile stresses due to material properties, thermal and mechanical loads. Making reliable prediction of stress fields, and thereby temperature cracking risk form an important part of the material modelling. The present study figures out the changes in thermal stresses and crack fields of the Kinta RCC dam at the end of the construction and its service life. Water temperature at various levels of the reservoir and its fluctuations were considered in the present study. The developed finite element program has been used in the analysis. Based on the obtained results, it is revealed that there is an increase in the thermal stresses after some years of dam completion. However, their location and distribution are mostly similar.
TL;DR: In this paper, the static behavior of a rotating cylindrical shell with surface bounded sensor and actuator in an axisymmetric hygrothermal condition is analyzed, and numerical results are presented to illuminate the effects of key parameters on the responses of the hybrid shell.
Abstract: The static behavior of a rotating cylindrical shell with surface bounded sensor and actuator in an axisymmetric hygrothermal condition is analyzed. The shell is simply supported and could be rested on an elastic foundation. The material properties of the shell and piezoelectric sensor and actuator are assumed to be functionally graded in the radial direction. Using the Fourier series expansion method through the longitudinal direction and the differential quadrature method (DQM) across the radial direction, and governing differential equations are solved. The validity of the present work was verified by comparisons with other published works. Numerical results are presented to illuminate the effects of key parameters on the responses of the hybrid shell.
TL;DR: In this paper, a homogeneous, isotropic thermoelastic half-space subjected to a time-dependent heat source on the surface, which is traction-free under the effect of rotation, is considered.
Abstract: The current article is concerned with three-dimensional problems for a homogeneous, isotropic thermoelastic half-space subjected to a time-dependent heat source on the surface, which is traction-free under the effect of rotation. The governing equations are taken in the context of fractional order generalized thermoelasticity (Green–Lindsay) theory. Normal mode analysis technique and eigenvalue approaches have been used to solve the non-dimensional equations. Numerical results for temperature, thermal stress and displacement distributions are presented graphically and discussed.
TL;DR: In this paper, a thermal buckling analysis for simply supported rectangular laminated composite plates that are covered with top and bottom piezoelectric actuators, and subjected to the combined action of thermal load and constant applied actuator voltage is presented.
Abstract: A thermal buckling analysis is presented for simply supported rectangular laminated composite plates that are covered with top and bottom piezoelectric actuators, and subjected to the combined action of thermal load and constant applied actuator voltage. The thermomechanical properties of composite and piezoelectric materials are assumed to be linear functions of the temperature. The formulations of the equations are based on the higher-order laminated plate theory of Reddy and using the Sanders nonlinear kinematic relations. The closed-form solutions for the buckling temperature are obtained through the Galerkin procedure and solving the resultant eigenvalue problem, which are convenient to be used in engineering design applications. Numerical examples are presented to verify the proposed method. The effects of the plate geometry, fiber orientation in composite layers, lay-up configuration, different utilized piezoelectric materials, temperature dependency of material properties, thermal conductivity, an...
TL;DR: In this paper, an exact analytical solution for thermal buckling analysis of functionally graded material (FGM) plates with clamped boundary condition subjected to uniform, linear, and non-linear temperature rises across the thickness direction is developed.
Abstract: In this research work, an exact analytical solution for thermal buckling analysis of functionally graded material (FGM) plates with clamped boundary condition subjected to uniform, linear, and non-linear temperature rises across the thickness direction is developed. Unlike any other theory, the number of unknown functions involved is only four, as against five in case of other shear deformation theories. The theory accounts for parabolic distribution of the transverse shear strains, and satisfies the zero traction boundary conditions on the surfaces of the plate without using shear correction factor. The material properties of FGM plate are assumed to be graded in the thickness direction according to a simple power-law distribution in terms of the volume fractions of the constituents. The governing equations are solved analytically for a plate with simply supported boundary conditions. Resulting equations are employed to obtain the closed-form solution for the thermal force resultant for each loading case...
TL;DR: In this article, the effects of high temperature on the stresses are more important than the high internal pressure, and an approximate homogeneous multilayer semi-analytical method is used successfully with adequate accuracy and finite layers.
Abstract: Thermoelasticity behavior of functionally graded thick hollow cylinders with power law and exponentially variations of material properties versus radius is studied analytically. Temperature, displacement and thermomechanical stress distributions are obtained and discussed. Approximate homogeneous multilayer semi-analytical method is used successfully with adequate accuracy and finite layers. Different combinations of ceramics and metals are checked out for thermoelastic stresses due to high temperature and internal pressure. We conclude that the approximate method is simple and has appropriate results. The effects of high temperature on the stresses are more important than the high internal pressure.
TL;DR: In this article, the elasticity solution of the simply-supported layered rectangular plates subjected to steady temperature loads was studied and an analytical method was developed to solve the temperature, stress and displacement fields in the plate.
Abstract: According to the exact three-dimensional (3D) thermoelasticity theory, the elasticity solution of the simply-supported layered rectangular plates subjected to steady temperature loads was studied. An analytical method was developed to solve the temperature, stress and displacement fields in the plate. Firstly, the general solutions of the temperature, displacements and stresses in a simply-supported isotropic layer were obtained by solving the 3-D heat conduction equation and the 3-D equations of elasticity respectively, which were expressed in the form of double Fourier series. Then, the temperature, displacement and stress relationships between the upper surface and the lower surface of the isotropic layer were derived. Based on the continuity of the temperature, the heat flux, the displacements and the stresses on the interface of two adjacent layers with different material properties, the recursive formulae of temperature, displacements and stresses between the bottom layer and the top layer of the la...
TL;DR: In this paper, the active vibration control of piezoelectric laminated beams under thermal load was studied using two noded finite elements with four mechanical and a variable number of electric potential degrees of freedom at each node.
Abstract: The dynamic analysis and the active vibration control of piezoelectric laminated beams under thermal load are presented. The beam is modeled using two noded finite elements with four mechanical and a variable number of electric potential degrees of freedom at each node. In the thickness direction, the thermal and the electric fields are approximated as piecewise linear across an arbitrary number of sublayers in a layer. Cubic Hermite interpolation is used for the deflection and electric potentials at the sublayers and linear interpolation is used for the axial displacement and the shear rotation. The thermal field is computed using a consistent six-noded thermal finite element with a quadratic interpolation along longitudinal direction and a linear interpolation along thickness direction. The temperature distribution and undamped natural frequencies are obtained for composite and sandwich beam under cantilever and clamped-clamped boundary conditions and compared with 2D-FE Abaqus results. The finite eleme...
TL;DR: In this paper, the authors presented specific new expressions for thermal stresses as Green's functions for a plane boundary value problem of steady-state thermoelasticity for a semi-layer.
Abstract: We present specific new expressions for thermal stresses as Green's functions for a plane boundary value problem of steady-state thermoelasticity for a semi-layer. We also obtain new integration formulas of Green's type, which determine the thermal stresses in the form of integrals of the products of the given distributed internal heat source, boundary temperature, and heat flux and derived kernels. Elementary functions results obtained are formulated in a theorem, which is proved using the harmonic integral representations method to derive thermal stresses Green's functions, which are written in terms of Green's functions for Poisson's equation. A new solution to particular two-dimensional boundary value problem for a semi-layer under a boundary constant temperature gradient is obtained in explicit form. Graphical presentations for thermal stresses Green's functions created by a unit heat source (line load in out-of-plane direction) and by a temperature gradient are also included.