ELEMENTOS FINITOS ENRIQUECIDOS PARA FLAMBAGEM E VIBRAÇÃO DE PLACAS / ENRICHED FINITE ELEMENTS FOR BUCKLING AND VIBRATION OF SHELLS

AUTOR(ES)

AMANDA JAREK

DATA DE PUBLICAÇÃO

2007

RESUMO

The focus of the present work is to developand evaluate enriched elements used to obtain critical loads, frequencies of vibration and respective modes for two-dimensional structural components (rectangular plates in bending under inplane compressive loading). The Rayleigh-Ritz approximation method has been employed, directed to the use of conventional finite elements enriched by internal and boundary additional displacements functions. The socalled internal functions are do not involve nodal and boundary displacements and rotations. The boundary functions are conceived to include displacements within the element and along one side, without involving any generalized nodal displacements. Two displacement function families were developed, the first with trigonometric additional terms and the second with polynomial additional terms. Critical loads and frequencies, and respective modes, are obtained by the use of elastic stifiness, geometric, and mass matrices, introduced in generalized eigenvalue problems. Numerical results are obtained by computational procedures using Maple software. The trigonometric additional functions, in spite of better convergence properties, demand greater computational effort. The basic elements are classical thin plate elements (Kirchhoff s theory) with three or four degrees of freedom per node, where the fourth degree of freedom corresponds to the mixed derivative (torsion). The results indicate that non- nodal additional functions require the use of elements with four freedom degrees by node to obtain convergence of critical loads and frequencies convergence in general situations. Other examples consist of preliminary approaches to include damage effects, in reinforced orthotropic plates, as modeling columns with wide rectangular sections and compressed slabs. The use of general additional functions combined with conventional elements represents a step on the development of a technique applicable to global and localized instability modes.

ASSUNTO(S)

numerical modeling finite elements structural instability elementos finitos modelagem numerica structural dynamics instabilidade estrutural dinamica de estruturas

Documentos Relacionados

• FORMULAÇÃO DE CASCAS ESPESSAS AXISSIMÉTRICAS UTILIZANDO ELEMENTOS FINITOS ENRIQUECIDOS
• Otimização de placas e cascas de materiais compósitos, utilizando algoritmos genéticos, redes neurais e elementos finitos
• DEVELOPMENT OF A SIMPLE FAMILY OF FINITE ELEMENTS FOR BEAMS, PLATES AND SHELLS INCLUDING THE EFFECT OF CROSS DISTORTION
• Métodos de Elementos Finitos e Diferenças Finitas para o Problema de Helmholtz
• Estudo comparativo entre elementos finitos isoparametricos das familias Serendipity e Lagrangeana para analise dinamica de placas e cascas