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The Singular Function Boundary Integral Method for singular Laplacian problems over circular sections

delete2010-11-01
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PRE
AI
E
Evgenia Christodoulou
C
Christos Xenophontos
G
Georgios C. Georgiou *
DOI:10.1016/j.amc.2010.08.012delete
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Abstract

Abstract

En 中文
The Singular Function Boundary Integral Method (SFBIM) for solving two-dimensional elliptic problems with boundary singularities is revisited. In this method the solution is approximated by the leading terms of the asymptotic expansion of the local solution, which are also used to weight the governing partial differential equation. The singular coefficients, i.e., the coefficients of the local asymptotic expansion, are thus primary unknowns. By means of the divergence theorem, the discretized equations are reduced to boundary integrals and integration is needed only far from the singularity. The Dirichlet boundary conditions are then weakly enforced by means of Lagrange multipliers, the discrete values of which are additional unknowns. In the case of two-dimensional Laplacian problems, the SFBIM converges exponentially with respect to the numbers of singular functions and Lagrange multipliers. In the present work the method is applied to Laplacian test problems over circular sectors, the analytical solution of which is known. The convergence of the method is studied for various values of the order p of the polynomial approximation of the Lagrange multipliers (i.e., constant, linear, quadratic, and cubic), and the exact approximation errors are calculated. These are compared to the theoretical results provided in the literature and their agreement is demonstrated. (C) 2010 Elsevier Inc. All rights reserved.
Keywords:
Boundary singularities
Boundary approximation methods
Lagrange multipliers
Stress intensity factors

Journal

Applied Mathematics and Computation cover
Applied Mathematics and Computation
IF:
3.4
Papers:
2.3W
Citations:
3.3W

Organization

U
University of Cyprus
Scholars:
4.3K
Papers: 5.0K
Citations: 3