scholarly journals A Novel MDD-Based BEM Model for Transient 3T Nonlinear Thermal Stresses in FGA Smart Structures

2020 ◽  
Author(s):  
Mohamed Abdelsabour Fahmy
Keyword(s):  
Thermal Stress ◽  
Boundary Element ◽  
Thermal Stresses ◽  
Smart Structures ◽  
Industrial Applications ◽  
Functionally Graded ◽  
Numerical Results ◽  
Stress Distributions ◽  
Proposed Model ◽  
Further Development

The main objective of this chapter is to introduce a novel memory-dependent derivative (MDD) model based on the boundary element method (BEM) for solving transient three-temperature (3T) nonlinear thermal stress problems in functionally graded anisotropic (FGA) smart structures. The governing equations of the considered study are nonlinear and very difficult if not impossible to solve analytically. Therefore, we develop a new boundary element scheme for solving such equations. The numerical results are presented highlighting the effects of the MDD on the temperatures and nonlinear thermal stress distributions and also the effect of anisotropy on the nonlinear thermal stress distributions in FGA smart structures. The numerical results also verify the validity and accuracy of the proposed methodology. The computing performance of the proposed model has been performed using communication-avoiding Arnoldi procedure. We can conclude that the results of this chapter contribute to increase our understanding on the FGA smart structures. Consequently, the results also contribute to the further development of technological and industrial applications of FGA smart structures of various characteristics.

Unsteady thermal stress analysis in three-dimensional problems by means of the thermoelastic displacement potential and the boundary element method

1990 ◽  
Vol 25 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Y Ochiai ◽  
R Ishida ◽  
T Sekiya
Keyword(s):  
Thermal Stress ◽  
Boundary Element Method ◽  
Boundary Element ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Stress Distributions ◽  
Displacement Potential ◽  
Thermal Displacements ◽  
Thermoelastic Displacement ◽  
Element Method

A numerical method to analyse unsteady thermal stresses in three-dimensional problems is proposed. It is shown that three-dimensional unsteady thermal stress problems can be easily solved without the volume integral by means of the thermoelastic displacement potential and the boundary element method. It is also shown that the time integral can be easily carried out analytically. In order to investigate the accuracy of this method, unsteady thermal stress distributions for a sphere and a circular cylinder are obtained. As a numerical example for which it is difficult to obtain the analytical solution, thermal displacements and surface stress distributions for a torus are obtained.

scholarly journals A new boundary element algorithm for modeling and simulation of nonlinear thermal stresses in micropolar FGA composites with temperature-dependent properties

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Mohamed Abdelsabour Fahmy
Keyword(s):  
Modeling And Simulation ◽  
Boundary Element ◽  
Thermal Stresses ◽  
Computation Time ◽  
Functionally Graded ◽  
Temperature Dependent ◽  
Time Step ◽  
Kirchhoff Transformation ◽  
Nonlinear Temperature ◽  
Temperature Dependent Properties

AbstractThe main aim of this article is to develop a new boundary element method (BEM) algorithm to model and simulate the nonlinear thermal stresses problems in micropolar functionally graded anisotropic (FGA) composites with temperature-dependent properties. Some inside points are chosen to treat the nonlinear terms and domain integrals. An integral formulation which is based on the use of Kirchhoff transformation is firstly used to simplify the transient heat conduction governing equation. Then, the residual nonlinear terms are carried out within the current formulation. The domain integrals can be effectively treated by applying the Cartesian transformation method (CTM). In the proposed BEM technique, the nonlinear temperature is computed on the boundary and some inside domain integral. Then, nonlinear displacement can be calculated at each time step. With the calculated temperature and displacement distributions, we can obtain the values of nonlinear thermal stresses. The efficiency of our proposed methodology has been improved by using the communication-avoiding versions of the Arnoldi (CA-Arnoldi) preconditioner for solving the resulting linear systems arising from the BEM to reduce the iterations number and computation time. The numerical outcomes establish the influence of temperature-dependent properties on the nonlinear temperature distribution, and investigate the effect of the functionally graded parameter on the nonlinear displacements and thermal stresses, through the micropolar FGA composites with temperature-dependent properties. These numerical outcomes also confirm the validity, precision and effectiveness of the proposed modeling and simulation methodology.

scholarly journals Thermal Stresses in Porous Materials under Thermal Shock by Cooling Medium-Infiltration Effect on Thermal Stress Distributions-

2004 ◽  
Vol 112 (1303) ◽  
pp. 172-178 ◽  
Author(s):  
Hiroaki TANAKA ◽  
Yuji MAKI ◽  
Kazuki TSUBOI ◽  
Sawao HONDA ◽  
Tadahiro NISHIKAWA ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Porous Materials ◽  
Thermal Shock ◽  
Thermal Stresses ◽  
Stress Distributions ◽  
Cooling Medium

Boundary Element Algorithm for Nonlinear Modeling and Simulation of Three-Temperature Anisotropic Generalized Micropolar Piezothermoelasticity with Memory-Dependent Derivative

2020 ◽  
Vol 12 (03) ◽  
pp. 2050027 ◽  
Author(s):  
Mohamed Abdelsabour Fahmy
Keyword(s):  
Boundary Element ◽  
Smart Materials ◽  
Nonlinear Modeling ◽  
Computation Time ◽  
Industrial Applications ◽  
Numerical Results ◽  
Element Formulation ◽  
Adaptive Smoothing ◽  
Nonlinear Properties ◽  
Element Algorithm

The main aim of this paper is to introduce a new memory-dependent derivative theory to contribute for increasing development of technological and industrial applications of anisotropic smart materials. This theory is called three-temperature anisotropic generalized micropolar piezothermoelasticity. The governing equations of the proposed theory are very difficult to solve analytically because of material anisotropy and its nonlinear properties. Therefore, we propose a new boundary element formulation for solving such equations. The efficiency of our proposed technique has been developed by using an adaptive smoothing and prolongation algebraic multigrid (aSP-AMG) preconditioner to reduce the computation time. The numerical results are presented highlighting the effects of the kernel function and time delay on the temperature and displacements. The numerical results also verify the validity and accuracy of the proposed methodology. It can be concluded from the numerical results of our current complex and general study that some well-known uncoupled, coupled and generalized theories of anisotropic micropolar piezothermoelasticity can be connected with the three-temperature radiative heat conduction to characterize the deformation of anisotropicmicropolar piezothermoelasticstructures in the context of memory-dependent derivative.

An Analysis of Thermo-Mechanical Behavior in a Multilayer Composite Pipe Under Temperature Variation

2010 ◽  
Author(s):  
Wei Yang ◽  
Jyhwen Wang
Keyword(s):  
Finite Element ◽  
Thermal Stress ◽  
Analytical Solution ◽  
Mechanical Behavior ◽  
Temperature Change ◽  
Thermal Stresses ◽  
Element Model ◽  
Functionally Graded ◽  
Element Analysis ◽  
Graded Materials

A generalized analytical solution of mechanical and thermal induced stresses in a multi-layer composite cylinder is presented. Based on the compatibility condition at the interfaces, an explicit solution of mechanical stress due to inner and outer surface pressures and thermal stress due to temperature change is derived. A finite element model is also developed to provide the comparison with the analytical solution. It was found that the analytical solutions are in good agreement with finite element analysis result. The analytical solution shows the non-linear dependency of thermal stress on the diameters, thicknesses and the material properties of the layers. It is also shown that the radial and circumferential thermal stresses depend linearly on the coefficients of thermal expansion of the materials and the temperature change. As demonstrated, this solution can also be applied to analyze the thermo-mechanical behavior of pipes coated with functionally graded materials.

Thermal stress analysis of in-plane two-directional functionally graded plates subjected to in-plane edge heat fluxes

2016 ◽  
Vol 232 (8) ◽  
pp. 693-716
Author(s):  
MK Apalak ◽  
MD Demirbas
Keyword(s):  
Mechanical Properties ◽  
Thermal Stress ◽  
Functionally Graded ◽  
Heat Fluxes ◽  
Material Composition ◽  
Stress Distributions ◽  
Thermal And Mechanical Properties ◽  
Functionally Graded Plates ◽  
Spatial Derivatives ◽  
Derivatives Of

This study investigates the thermal stress and deformation states of bi-directional functionally graded clamped plates subjected to constant in-plane heat fluxes along two ceramic edges. The material properties of the functionally graded plates were assumed to vary with a power law along two in-plane directions not through the plate thickness direction. The spatial derivatives of thermal and mechanical properties of the material composition were considered, and the effects of the bi-directional composition variations and spatial derivative terms on the displacement, strain and stress distributions were also investigated. The heat conduction and Navier equations describing the two-dimensional thermo-elastic problem were discretized using finite-difference method, and the set of linear equations were solved using the pseudo singular value method. The compositional gradient exponents and the spatial derivatives of thermal and mechanical properties of the material composition were observed to play an important role especially on the heat transfer durations, the displacement and strain distributions, but had a minor effect on the temperature and stress distributions.

A Three-Dimensional Treatment of Transient Thermal Stresses in a Circular Cylinder Due to an Arbitrary Heat Supply

1978 ◽  
Vol 45 (4) ◽  
pp. 817-821 ◽  
Author(s):  
Y. Takeuti ◽  
N. Noda
Keyword(s):  
Thermal Stress ◽  
Circular Cylinder ◽  
Cylindrical Surface ◽  
Heat Supply ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Numerical Results ◽  
Stress Problem ◽  
Transient Thermal Stress ◽  
Transient Thermal

We deal with a transient thermal stress problem in an infinitely long circular cylinder due to a nonuniform heat supply in circumferential and longitudinal directions on its cylindrical surface. The analysis is developed using the Boussinesq-Papkovich functions. Numerical results are given for several forms of heat supply.

Quasi-static thermal stresses due to a concentrated moving heat source in a thin plate

2016 ◽  
Vol 22 (2) ◽  
pp. 243-256
Author(s):  
Amir Reza Shahani ◽  
Samad Kalani
Keyword(s):  
Thermal Stress ◽  
Stress Field ◽  
Heat Source ◽  
Thin Plate ◽  
Thermal Stresses ◽  
Static Solution ◽  
Stress Distributions ◽  
Moving Heat Source ◽  
Displacement Potential ◽  
Thermal Stress Field

Temperature and thermal stress distributions in a two-dimensional infinite thin plate subjected to a moving heat source with variable power and velocity are obtained by solving quasi-static thermoelasticity equations analytically with the aid of a thermoelastic displacement potential. The results show good agreement with experimental data for a stationary source with constant power and with a steady-state analytical solution in the open literature. It is shown that the quasi-static solution can predict changes of the thermal stress field during the movement of the heat source, and can give the effect of changes of power and velocity of the heat source on the thermal stress field during its movement.

Computational Fluid Dynamics Modeling of Flashing Flow in Convergent-Divergent Nozzle

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Quang Dang Le ◽  
Riccardo Mereu ◽  
Giorgio Besagni ◽  
Vincenzo Dossena ◽  
Fabio Inzoli
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluid Dynamic ◽  
Industrial Applications ◽  
Numerical Results ◽  
Sensitivity Analyses ◽  
Dynamics Modeling ◽  
Thermal Nonequilibrium ◽  
Nonequilibrium Effect ◽  
Proposed Model

In this paper, a computational fluid dynamics model of flashing flow, which considers the thermal nonequilibrium effect, has been proposed. In the proposed model, based on the two-phase mixture approach, the phase-change process depends on the difference between the vaporization pressure and the vapor partial pressure. The thermal nonequilibrium effect has been included by using ad hoc modeling of the boiling delay. The proposed model has been applied to the case of two-dimensional axisymmetric convergent-divergent nozzle, which is representative of well-known applications in nuclear and energy engineering applications (e.g., the primary flow in the motive nozzle of ejectors). The numerical results have been validated based on a benchmark case from the literature and have been compared with the numerical results previously obtained by different research groups. The proposed approach has shown a good level of agreement as regards the global and the local experimental fluid dynamic quantities. In addition, sensitivity analyses have been carried out concerning (a) grid independency, (b) turbulence modeling approaches, (c) near-wall treatment approaches, (d) turbulence inlet parameters, and (e) semi-empirical coefficients. In conclusion, the present paper aims to provide guidelines for the simulation of flash boiling flow in industrial applications.

Predicting winding stresses for wound coils of linear orthotropic material

2004 ◽  
Vol 218 (1) ◽  
pp. 13-25 ◽  
Author(s):  
F R de Hoog ◽  
M Cozijnsen ◽  
W Y D Yuen ◽  
W Y D Yuen ◽  
H-N Huynh
Keyword(s):  
Orthotropic Material ◽  
Industrial Applications ◽  
Numerical Results ◽  
Inverse Solution ◽  
Stress Profile ◽  
Stress Distributions ◽  
Forward Solution ◽  
Perfect Agreement ◽  
Winding Tension ◽  
The Given

This paper examines centre winding of coils under the assumption that the material is linear and orthotropic. A radically different approach is taken in the analysis of residue stresses in the coils. Instead of the forward solution of determining the residue stresses from the given winding stress profile, as traditionally adopted in this field of research, an inverse solution is obtained in which the winding tension profile is determined from the prescribed residue stresses. This approach offers significant advantages in industrial applications, since the preferred residue stress distributions to prevent coiling problems, such as tight-bore collapses and coil slump, are often specified. Numerical results from the inverse solution are found to be in perfect agreement with the forward solution.

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