Subdomain-based error techniques for generalized finite element approximations of problems with singular stress fields

Felício B. Barros, Clovis S. De Barcellos, C. Armando Duarte, Diego A.F. Torres

Research output: Contribution to journalArticle

Abstract

This paper considers four types of error measures, each tailored to the generalized finite element method. Particular attention is given to two-dimensional elasticity problems with singular stress fields. The first error measure is obtained using the equilibrated element residual method. The other three estimators overcome the necessity of equilibrating the residue by employing a subdomain strategy. In this strategy, the partition of unity (PoU) property is used to decompose the error problem into local contributions over each patch of elements. The residual functional of the error problem is the same for the subdomain estimators, but the bi-linear form is different for each one of them. In the second estimator, the bi-linear form is weighted by the PoU functions associated with the patch over which the error problem is stated. No weighting appears in the bi-linear form of the third estimator. The fourth measure is proposed as an alternative strategy, in which the products of the PoU functions and test functions are introduced as weights in the weighted integral statement of the differential equation describing the error problem. The linear form of the local error problem is then identical to that of the other subdomain techniques, while the bi-linear form is stated differently, with the PoU functions directly multiplying the test functions. The goal of this study is to investigate the performance of the four estimators in two-dimensional elasticity problems with geometries that produce singularities in the stress field and concentration of the error in the numerical solution.

Original languageEnglish (US)
Pages (from-to)1395-1415
Number of pages21
JournalComputational Mechanics
Volume52
Issue number6
DOIs
StatePublished - Dec 2013

Keywords

  • Error estimator
  • Extended finite element method
  • Generalized finite element method
  • Subdomain-based residual error estimators
  • Two-dimensional singular elasticity singular fields

ASJC Scopus subject areas

  • Computational Mechanics
  • Ocean Engineering
  • Mechanical Engineering
  • Computational Theory and Mathematics
  • Computational Mathematics
  • Applied Mathematics

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