On the asymptotic exactness of error estimators for linear triangular finite elements

This paper deals with a-posteriori error estimates for piecewise linear finite element approximations of elliptic problems. We analyze two estimators based on recovery operators for the gradient of the approximate solution. By using superconvergence results we prove their asymptotic exactness under...

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Detalhes bibliográficos
Autores: Durán, Ricardo Guillermo, Muschietti, María Amelia, Rodríguez, Rodolfo
Formato: artículo
Estado:Versión publicada
Fecha de publicación:1991
País:Argentina
Recursos:Universidad Nacional de La Plata
Repositorio:SEDICI (UNLP)
Idioma:inglés
OAI Identifier:oai:sedici.unlp.edu.ar:10915/134060
Acesso em linha:http://sedici.unlp.edu.ar/handle/10915/134060
Access Level:acceso abierto
Palavra-chave:Ciencias Exactas
Matemática
elliptic problems
superconvergence
error estimator
Descrição
Resumo:This paper deals with a-posteriori error estimates for piecewise linear finite element approximations of elliptic problems. We analyze two estimators based on recovery operators for the gradient of the approximate solution. By using superconvergence results we prove their asymptotic exactness under regularity assumptions on the mesh and the solution. One of the estimators can be easily computed in terms of the jumps of the gradient of the finite element approximation. This estimator is equivalent to the error in the energy norm under rather general conditions. However, we show that for the asymptotic exactness, the regularity assumption on the mesh is not merely technical. While doing this, we analyze the relation between superconvergence and asymptotic exactness for some particular examples.