A finite strain quadrilateral based on least-squares assumed strains

• Tipo: Artigo em Revista Científica Internacional
• Data: 2015

Autores

Areias, P. (Autor) Outra; Rabczuk, T. (Autor) Outra; César de Sá, J. (Autor) FEUP

Revista

Título: Engineering Structures

Vol. 100

Páginas: 1-16

ISSN: 0141-0296

Editora: Elsevier

Indexação

ISI Web of Knowledge - 2 Citações

Scopus - 4 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia mecânica

CORDIS: Ciências Tecnológicas > Engenharia > Engenharia mecânica

Outras Informações

ID Authenticus: P-00G-BDR

DOI: 10.1016/j.engstruct.2015.05.035

Abstract (EN): When compared with advanced triangle formulations (e.g. Allman triangle and Arnold MINI), specially formulated low order quadrilateral elements still present performance advantages for bending-dominated and quasi-incompressible problems. However, simultaneous mesh distortion insensitivity and satisfaction of the Patch test is difficult. In addition, many enhanced-assumed (EAS) formulations show hourglass patterns in finite strains for large values of compression or tension; EAS elements often present convergence difficulties in Newton iteration, particularly in the presence of high bulk modulus or nearly-incompressible plasticity. Alternatively, we discuss the adequacy of a new assumed-strain 4-node quadrilateral for problems where high strain gradients are present. Specifically, we use relative strain projections to obtain three versions of a selectively-reduced integrated formulation complying a priori with the patch test. Assumed bending behavior is directly introduced in the higher-order strain term. Elements make use of least-square fitting and are generalization of classical (B) over bar and (F) over bar techniques. We avoid ANS (assumed natural strains) by defining the higher-order strain in contravariant/contravariant coordinates with a fixed frame. The kinematical part of the constitutive updating is based on quadratic incremental Green-Lagrange strains. Linear tests and both hyperelastic and elasto-plastic constitutive laws are used to test the element in realistic cases.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 16