The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Glaucio H Paulino - One of the best experts on this subject based on the ideXlab platform.
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the simple boundary element method for transient heat conduction in functionally graded materials
Computer Methods in Applied Mechanics and Engineering, 2004Co-Authors: Alok Sutradhar, Glaucio H PaulinoAbstract:Abstract This paper presents a “simple” boundary element method for transient heat conduction in functionally graded materials, which leads to a boundary-only formulation without any domain discretization. For a broad range of functional material variation (quadratic, exponential and trigonometric) of thermal conductivity and specific heat, the non-Homogeneous Problem can be transformed into the standard Homogeneous diffusion Problem. A three-dimensional boundary element implementation, using the Laplace transform approach and the Galerkin approximation, is presented. The time dependence is restored by numerically inverting the Laplace transform by means of the Stehfest algorithm. A number of numerical examples demonstrate the efficiency of the method. The results of the test examples are in excellent agreement with analytical solutions and finite element simulation results.
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a simple boundary element method for Problems of potential in non Homogeneous media
International Journal for Numerical Methods in Engineering, 2004Co-Authors: Alok Sutradhar, Glaucio H PaulinoAbstract:A simple boundary element method for solving potential Problems in non-Homogeneous media is presented. A physical parameter (e.g. heat conductivity, permeability, permittivity, resistivity, magnetic permeability) has a spatial distribution that varies with one or more co-ordinates. For certain classes of material variations the non-Homogeneous Problem can be transformed to known Homogeneous Problems such as those governed by the Laplace, Helmholtz and modified Helmholtz equations. A three-dimensional Galerkin boundary element method implementation is presented for these cases. However, the present development is not restricted to Galerkin schemes and can be readily extended to other boundary integral methods such as standard collocation. A few test examples are given to verify the proposed formulation. The paper is supplemented by an Appendix, which presents an ABAQUS user-subroutine for graded finite elements. The results from the finite element simulations are used for comparison with the present boundary element solutions.
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A simple boundary element method for Problems of potential in non‐Homogeneous media
International Journal for Numerical Methods in Engineering, 2004Co-Authors: Alok Sutradhar, Glaucio H PaulinoAbstract:A simple boundary element method for solving potential Problems in non-Homogeneous media is presented. A physical parameter (e.g. heat conductivity, permeability, permittivity, resistivity, magnetic permeability) has a spatial distribution that varies with one or more co-ordinates. For certain classes of material variations the non-Homogeneous Problem can be transformed to known Homogeneous Problems such as those governed by the Laplace, Helmholtz and modified Helmholtz equations. A three-dimensional Galerkin boundary element method implementation is presented for these cases. However, the present development is not restricted to Galerkin schemes and can be readily extended to other boundary integral methods such as standard collocation. A few test examples are given to verify the proposed formulation. The paper is supplemented by an Appendix, which presents an ABAQUS user-subroutine for graded finite elements. The results from the finite element simulations are used for comparison with the present boundary element solutions.
Alok Sutradhar - One of the best experts on this subject based on the ideXlab platform.
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the simple boundary element method for transient heat conduction in functionally graded materials
Computer Methods in Applied Mechanics and Engineering, 2004Co-Authors: Alok Sutradhar, Glaucio H PaulinoAbstract:Abstract This paper presents a “simple” boundary element method for transient heat conduction in functionally graded materials, which leads to a boundary-only formulation without any domain discretization. For a broad range of functional material variation (quadratic, exponential and trigonometric) of thermal conductivity and specific heat, the non-Homogeneous Problem can be transformed into the standard Homogeneous diffusion Problem. A three-dimensional boundary element implementation, using the Laplace transform approach and the Galerkin approximation, is presented. The time dependence is restored by numerically inverting the Laplace transform by means of the Stehfest algorithm. A number of numerical examples demonstrate the efficiency of the method. The results of the test examples are in excellent agreement with analytical solutions and finite element simulation results.
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a simple boundary element method for Problems of potential in non Homogeneous media
International Journal for Numerical Methods in Engineering, 2004Co-Authors: Alok Sutradhar, Glaucio H PaulinoAbstract:A simple boundary element method for solving potential Problems in non-Homogeneous media is presented. A physical parameter (e.g. heat conductivity, permeability, permittivity, resistivity, magnetic permeability) has a spatial distribution that varies with one or more co-ordinates. For certain classes of material variations the non-Homogeneous Problem can be transformed to known Homogeneous Problems such as those governed by the Laplace, Helmholtz and modified Helmholtz equations. A three-dimensional Galerkin boundary element method implementation is presented for these cases. However, the present development is not restricted to Galerkin schemes and can be readily extended to other boundary integral methods such as standard collocation. A few test examples are given to verify the proposed formulation. The paper is supplemented by an Appendix, which presents an ABAQUS user-subroutine for graded finite elements. The results from the finite element simulations are used for comparison with the present boundary element solutions.
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A simple boundary element method for Problems of potential in non‐Homogeneous media
International Journal for Numerical Methods in Engineering, 2004Co-Authors: Alok Sutradhar, Glaucio H PaulinoAbstract:A simple boundary element method for solving potential Problems in non-Homogeneous media is presented. A physical parameter (e.g. heat conductivity, permeability, permittivity, resistivity, magnetic permeability) has a spatial distribution that varies with one or more co-ordinates. For certain classes of material variations the non-Homogeneous Problem can be transformed to known Homogeneous Problems such as those governed by the Laplace, Helmholtz and modified Helmholtz equations. A three-dimensional Galerkin boundary element method implementation is presented for these cases. However, the present development is not restricted to Galerkin schemes and can be readily extended to other boundary integral methods such as standard collocation. A few test examples are given to verify the proposed formulation. The paper is supplemented by an Appendix, which presents an ABAQUS user-subroutine for graded finite elements. The results from the finite element simulations are used for comparison with the present boundary element solutions.
David Dureisseix - One of the best experts on this subject based on the ideXlab platform.
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A multi‐scale reduced‐order‐model strategy for transient thermo‐elasticity with variable micro‐structure
International Journal for Numerical Methods in Engineering, 2021Co-Authors: Mainak Bhattacharyya, David DureisseixAbstract:This article deals with thermo-elastic computation of heterogeneous structures containing quasi-periodic micro-structures having variable properties (geometric and/or material) using reduced order modelling. Such heterogeneous structure is extremely expensive to simulate using classical finite element methods, as the level of discretisation required to capture the micro-structural effects, is too fine. Based on the asymptotic homogenisation theory, the multi-scale technique explores the micro-macro behaviour for thermo-elasticity. Considering each integration point of the macro-structure consists of an underlying locally-periodic micro-structure, the overall Problem is basically separated into a Homogeneous Problem defined over the macro-structure and a heterogeneous Problem defined over each micro-structure. Even though the usage of multi-scale strategy helps in the reduction of numerical expense, it still deals with a full order finite element solution for the macro-Problem and each micro-Problem. Using a 2-fold reduced order modelling further accentuates the cost reduction and provides a robust solution in a reduced space: (i) as an offline pre-computation stage for the micro-structural Problem, and (ii) as an online process that can embed adaptivity for the macroscopic Problem.
Mainak Bhattacharyya - One of the best experts on this subject based on the ideXlab platform.
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A multi‐scale reduced‐order‐model strategy for transient thermo‐elasticity with variable micro‐structure
International Journal for Numerical Methods in Engineering, 2021Co-Authors: Mainak Bhattacharyya, David DureisseixAbstract:This article deals with thermo-elastic computation of heterogeneous structures containing quasi-periodic micro-structures having variable properties (geometric and/or material) using reduced order modelling. Such heterogeneous structure is extremely expensive to simulate using classical finite element methods, as the level of discretisation required to capture the micro-structural effects, is too fine. Based on the asymptotic homogenisation theory, the multi-scale technique explores the micro-macro behaviour for thermo-elasticity. Considering each integration point of the macro-structure consists of an underlying locally-periodic micro-structure, the overall Problem is basically separated into a Homogeneous Problem defined over the macro-structure and a heterogeneous Problem defined over each micro-structure. Even though the usage of multi-scale strategy helps in the reduction of numerical expense, it still deals with a full order finite element solution for the macro-Problem and each micro-Problem. Using a 2-fold reduced order modelling further accentuates the cost reduction and provides a robust solution in a reduced space: (i) as an offline pre-computation stage for the micro-structural Problem, and (ii) as an online process that can embed adaptivity for the macroscopic Problem.
Ramón Quintanilla - One of the best experts on this subject based on the ideXlab platform.
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Some qualitative results for the linear theory of thermo-microstretch elastic solids
International Journal of Engineering Science, 1995Co-Authors: F. Bofill, Ramón QuintanillaAbstract:This paper is concerned with the linear theory of thermo-microstretch elastic solids. In Section 3 we present a uniqueness theorem for the solutions of this Problem. This result covers a larger class of Problems than the uniqueness theorem stated in [5]. An existence theorem is also presented in Section 4. In Section 5 we study the asymptotic behavior for the solutions of the Homogeneous Problem.
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On the grade consistent theory of micropolar thermoelasticity
Journal of Thermal Stresses, 1992Co-Authors: Dorin Ieşan, Ramón QuintanillaAbstract:Abstract A grade consistent micropolar theory of thermoeluslicily is considered. First some results concerning reciprocity, variational characterization of the solution, existence, and uniqueness are established. Then, the theory of Homogeneous and isotropic solids is studied. A solution of Cauchy-Kovalevski-Somigliana type and the fundamental solutions in the case of steady vibrations are established. We also study the asymptotic behavior for the Homogeneous Problem.