The Experts below are selected from a list of 5559 Experts worldwide ranked by ideXlab platform
V Sladek - One of the best experts on this subject based on the ideXlab platform.
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application of local boundary integral equation method into micropolar elasticity
Engineering Analysis With Boundary Elements, 2003Co-Authors: J Sladek, V SladekAbstract:A new meshless method for solving boundary value problems in micropolar elasticity is presented. The method is based on the local boundary integral equation (LBIE) method with the moving least squares approximation of physical quantities. Randomly scattered nodes are utilized for interpolation of field data. Every node is surrounded by a simple surface centered at the Collocation Point in the LBIE method. On the surface of subdomains the LBIEs are written. Fundamental solutions corresponding to uncoupled governing equations are derived. To eliminate the traction vector in the LBIE, the modified fundamental solution is introduced.
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local boundary integral equation lbie method for solving problems of elasticity with nonhomogeneous material properties
Computational Mechanics, 2000Co-Authors: J Sladek, V Sladek, S N AtluriAbstract:This paper presents the local boundary integral formulation for an elastic body with nonhomogeneous material properties. All nodal Points are surrounded by a simple surface centered at the Collocation Point. Only one nodal Point is included in each the sub-domain. On the surface of the sub-domain, both displacements and traction vectors are unknown generally. If a modified fundamental solution, for governing equation, which vanishes on the local boundary is chosen, the traction value is eliminated from the local boundary integral equations for all interior Points. For every sub-domain, the material constants correspond to those at the Collocation Point at the center of sub-domain. Meshless and polynomial element approximations of displacements on the local boundaries are considered in the numerical analysis.
J Sladek - One of the best experts on this subject based on the ideXlab platform.
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application of local boundary integral equation method into micropolar elasticity
Engineering Analysis With Boundary Elements, 2003Co-Authors: J Sladek, V SladekAbstract:A new meshless method for solving boundary value problems in micropolar elasticity is presented. The method is based on the local boundary integral equation (LBIE) method with the moving least squares approximation of physical quantities. Randomly scattered nodes are utilized for interpolation of field data. Every node is surrounded by a simple surface centered at the Collocation Point in the LBIE method. On the surface of subdomains the LBIEs are written. Fundamental solutions corresponding to uncoupled governing equations are derived. To eliminate the traction vector in the LBIE, the modified fundamental solution is introduced.
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local boundary integral equation lbie method for solving problems of elasticity with nonhomogeneous material properties
Computational Mechanics, 2000Co-Authors: J Sladek, V Sladek, S N AtluriAbstract:This paper presents the local boundary integral formulation for an elastic body with nonhomogeneous material properties. All nodal Points are surrounded by a simple surface centered at the Collocation Point. Only one nodal Point is included in each the sub-domain. On the surface of the sub-domain, both displacements and traction vectors are unknown generally. If a modified fundamental solution, for governing equation, which vanishes on the local boundary is chosen, the traction value is eliminated from the local boundary integral equations for all interior Points. For every sub-domain, the material constants correspond to those at the Collocation Point at the center of sub-domain. Meshless and polynomial element approximations of displacements on the local boundaries are considered in the numerical analysis.
S N Atluri - One of the best experts on this subject based on the ideXlab platform.
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local boundary integral equation lbie method for solving problems of elasticity with nonhomogeneous material properties
Computational Mechanics, 2000Co-Authors: J Sladek, V Sladek, S N AtluriAbstract:This paper presents the local boundary integral formulation for an elastic body with nonhomogeneous material properties. All nodal Points are surrounded by a simple surface centered at the Collocation Point. Only one nodal Point is included in each the sub-domain. On the surface of the sub-domain, both displacements and traction vectors are unknown generally. If a modified fundamental solution, for governing equation, which vanishes on the local boundary is chosen, the traction value is eliminated from the local boundary integral equations for all interior Points. For every sub-domain, the material constants correspond to those at the Collocation Point at the center of sub-domain. Meshless and polynomial element approximations of displacements on the local boundaries are considered in the numerical analysis.
Edson Denner Leonel - One of the best experts on this subject based on the ideXlab platform.
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mechanical modelling of three dimensional cracked structural components using the isogeometric dual boundary element method
Applied Mathematical Modelling, 2018Co-Authors: Sergio Gustavo Ferreira Cordeiro, Edson Denner LeonelAbstract:Abstract The mechanical modelling of cracked structural components using Linear Elastic Fracture Mechanics (LEFM) concepts has major importance for structural integrity analysis. In addition, the Isogeometric Analysis (IGA) has recently emerged as a robust approach for analysing structural components directly from Computer-Aided Design (CAD) models. In this context, this study presents an isogeometric Dual Boundary Element Method (DBEM) formulation for the mechanical modelling of cracked three-dimensional structural components. The isogeometric formulation is based on NURBS surfaces. It was implemented regarding any polynomial orders for the basis functions. The strong singular and hypersingular integrals required by the DBEM are evaluated by the Guiggiani method. The C1 continuity is achieved at any Collocation Point inside the NURBS surfaces, ensuring the existence of hypersingular integrals. Consequently, discontinuous boundary elements are no longer required for the isogeometric DBEM, which enables an important reduction on the amount of Collocation Points at the crack surfaces. The Stress Intensity Factors (SIF) are evaluated by the displacement correlation technique. The geometrically exact description of the crack front eliminates the approximation errors related to the rotation of the displacement discontinuities with respect to the crack front local coordinate systems. Three applications involving edge and embedded cracks are presented. The isogeometric formulation provided accurate SIF results with less degrees of freedom at the crack surfaces in comparison with the conventional DBEM approach. However, the isogeometric DBEM approach has shown to be more expensive in terms of computational time.
Francesco Ciucci - One of the best experts on this subject based on the ideXlab platform.
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influence of the discretization methods on the distribution of relaxation times deconvolution implementing radial basis functions with drttools
Electrochimica Acta, 2015Co-Authors: Ting Hei Wan, Mattia Saccoccio, Chi Chen, Francesco CiucciAbstract:Abstract The distribution of relaxation times (DRT) is an approach that can extract time characteristics of an electrochemical system from electrochemical impedance spectroscopy (EIS) measurements. Computing the DRT is difficult because it is an intrinsically ill-posed problem often requiring regularization. In order to improve the estimation of the DRT and to better control its error, a suitable discretization basis for the regularized regression needs to be chosen. However, this aspect has been invariably overlooked in the specialized literature. Pseudo-spectral methods using radial basis functions (RBFs) are, in principle, a better choice in comparison to other discretization basis, such as piecewise linear (PWL) functions, because they may achieve fast convergence. Furthermore, they can yield improved estimation by extending the estimated DRT to the entire frequency spectrum, if the underlying DRT decays to zero sufficiently fast outside the measured frequency range. Additionally, their implementation is relatively easier than other types of pseudo-spectral methods since they do not require ad hoc Collocation Point distributions. The as-developed novel RBF-based DRT framework was tested against controlled synthetic EIS spectra and real experimental data. Our results indicate that the RBF discretization performance is comparable with that of the PWL discretization at normal data collection range, and with improvement when the EIS acquisition is incomplete. In addition, we also show that applying RBF discretization for deconvolving the DRT problem can lead to faster numerical convergence rate as compared with that of PWL discretization only at error free situation. As a companion to this work we have developed a MATLAB GUI toolbox, which can be used to solve DRT regularization problems.