Singular Integrals
Mostrando 1-12 de 17 artigos, teses e dissertações.
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1. Boundary Layer Effects in a Finite Linearly Elastic Peridynamic Bar
Abstract The peridynamic theory is an extension of the classical continuum mechanics theory. The peridynamic governing equations involve integrals of interaction forces between near particles separated by finite distances. These forces depend upon the relative displacements between material points within a body. On the other hand, the classical governing equ
Lat. Am. j. solids struct.. Publicado em: 22/10/2018
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2. Transverse Motions of Rectangular Plates Resting on Elastic Foundation and Under Concentrated Masses Moving at Varying Velocities
AbstractThis study concerns the dynamic characteristics of a prestressed isotropic, rectangular plate continuously supported by an elastic foundation and carrying accelerating mass M. Closed form solutions of the governing fourth order partial differential equations with variable and singular coefficients are presented. For the two-dimensional plate problem,
Lat. Am. j. solids struct.. Publicado em: 2015-07
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3. Comparação de desempenho entre as formulações singular e ipersingular do método dos elementos de contorno
In this work, the Singular and Hypersingular Formulations of the Boundary Element Method are presented and their results are compared on two dimensional stationary scalar field problems , governed by the Laplace Equation. In the conventional formulations of the Boundary Element Method, a special attention must be given to the singular integrations that appea
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/05/2009
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4. Operadores de Calderón-Zygmund e o teorema T1
In this work, we present necessary and suficient conditions for that an operator of Calderón-Zygmund type can be extended to a bounded operator on L2. By using results of interpolation and cancellation conditions on the kernel to obtain the boundeness in Lp, for all 1
Publicado em: 2009
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5. Formulação dual em mecânica da fratura utilizando elementos de contorno curvos de ordem qualquer / Dual boundary element formulation in fracture mechanics using curved element of any order
This work presents the dual boundary element formulation applied to linear crack problem. The goal of this research is the evaluation of stress intensity factor for two-dimensional crack problem using three different techniques, which are: the technique of correlation of displacements, the technique based on the state of tension at the crack tip and J integr
Publicado em: 2009
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6. Algoritmos de integração eficientes para o método dos elementos de contorno tridimensional. / Efficient integration algorithms for the three-dimensional boundary element method.
In this work the three-dimensional elastic problem is analyzed by the boundary element method using the Kelvin fundamental solution. Two main formulations are applied. The first one uses the classical Kelvin fundamental solution and the other, hyper-singular, uses a derivative of the Kelvin fundamental solution. The boundary is discretized by flat triangular
Publicado em: 2001
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7. IMPLEMENTACIÓN NUMÉRICA PARA EL ESTUDIO DE FUNDACIONES FLEXIBLES EN SUELOS ESTRATIFICADOS / NUMERICAL ANALYSIS OF FLEXIBLE FOOTINGS ON STRATIFIED SOILS / IMPLEMENTAÇÃO NUMÉRICA PARA ESTUDO DE FUNDAÇÕES FLEXÍVEIS EM SOLOS ESTRATIFICADOS
Many problems of geotechnical engineering can be solved by superposition of the fundamental singular solutions to the governing differential equations. In the dissertation, the mechanical behavior of a flexible footing is investigated, in terms of stress and settlement distributions, considered some basic fundamental solutions published in literature. These
Publicado em: 2000
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8. TÉCNICAS AVAÇADAS DE INTEGRAÇÃO NUMÉRICA E PROGRAMAÇÃO ORIENTADA A OBJETOS APLICADAS A MÉTODOS DE ELEMENTOS DE CONTORNO / ADVANCED NUMERICAL INTEGRATION TECHNIQUES AND OBJECT ORIENTED PROGRAMMING APPLIED TO BOUNDARY ELEMENT METHODS
In Boundary Element Method analysis, the integration procedure is one of the most important tasks, since one has to deal with singular and quasi-singular integrals which introduce numerical errors in the results, if they are not evaluated adequately. In the last years, several researchers have suggested different techniques with the aim of handling the probl
Publicado em: 1998
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9. Singular integrals related to the Radon transform and boundary value problems
Two classes of integral operators are introduced that combine features of Calderón—Zygmund singular integrals, the Hilbert integral, and the Radon transform. Examples and applications arising from integral geometry and several complex variables are discussed.
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10. Distribution Function Inequalities for Singular Integrals
This paper describes some distribution function inequalities between maximal functions and singular integral operators.
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11. Oscillatory singular integrals and harmonic analysis on nilpotent groups
Several related classes of operators on nilpotent Lie groups are considered. These operators involve the following features: (i) oscillatory factors that are exponentials of imaginary polynomials, (ii) convolutions with singular kernels supported on lower-dimensional submanifolds, (iii) validity in the general context not requiring the existence of dilations
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12. SINGULAR INTEGRALS AND THE PRINCIPAL SERIES
The L2 theory of singular integral operators on nilpotent Lie groups is studied, extending known results for IRn. The intertwining operators for the representations of the simple Lie groups of real rank one turn out to be of this type. As a result we determine which representations of the principal series of these groups are irreducible.