Master's Dissertation
DOI
https://doi.org/10.11606/D.18.2008.tde-30062009-110011
Document
Author
Full name
Charlton Okama de Souza
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Carlos, 2008
Supervisor
Committee
Proença, Sergio Persival Baroncini (President)
Pavanello, Renato
Savassi, Walter
Title in Portuguese
Formulação híbrida-Trefftz com enriquecimento seletivo: aplicação a problemas bidimensionais da elasticidade
Keywords in Portuguese
Formulação híbrida-Trefftz de tensão
Método da partição
Método dos elementos finitos
Abstract in Portuguese
Title in English
The hybrid-Trefftz formulation with selective enrichment: application to two-dimensional problems in elasticity
Keywords in English
Finite elements method
Generalized finite elements method
Hybrid-Trefftz stress formulation
Splitting method
Abstract in English
This work is inserted in the context of unconventional formulations in the finite elements method. Particularly, some aspects of the generalized finite elements method (GFEM) and the classic p-refinement are introduced in the well known hybrid-Trefftz stress formulation for the two dimensional elasticity. The presented formulation approximates two independent fields: the one of stresses in the elements domain and the one of displacements in the boundaries of the elements. Based on the enrichment structure centered in clouds, proposed by the GFEM, some regions, formed by a group of elements and boundaries of elements where the approximation space is adequately enriched by the p-refinement, can be opportunely selected. In this context, self-equilibrated stress fields, derived from the solution of the Navier equation, are used to compose the approximation in the elements domain, whereas the displacements field in the borders of the elements is built from specific approximation bases, that is, the initial base formed by linear shape functions, or, bases enriched with hierarchical polynomials, nonhierarchical ones and trigonometric functions. Also, although preliminarily, a study of the multiple-cracked panels is done using the Splitting Method with a hybrid-Trefftz formulation and a selective enrichment. The numeric analyses done revealed, in general, a high performance formulation characterized by a great capacity of approximation the stress fields and displacements, high numeric robustness and reduced computer expenditure.