A variationally consistent generalized variable formulation for enhanced strain finite elements

✍ Scribed by Perego, Umberto

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 126 KB
• Volume: 16
• Category: Article
• ISSN: 1069-8299
• DOI: 10.1002/(sici)1099-0887(200003)16:3<151::aid-cnm309>3.0.co;2-5

✦ Synopsis

The so-called enhanced strain ÿnite elements are based on the enrichment of the standard compatible strain ÿeld by the introduction of additional, non-compatible strains. This class of elements can be derived starting from a partial Hu-Washizu variational principle. However, since in the original enhanced strain formulation the stress ÿeld is eliminated from the formulation, a separate least-squares procedure had to be implemented for a variational derivation of the stress ÿeld. A three-ÿeld generalized variable approach incorporating strain enhancement is proposed in the present paper within the context of linear elastic structural problems. It is shown how the original two-ÿeld enhanced strain method can be naturally recovered by suitably choosing the strain model. For this case a straightforward, but still variationally consistent stress recovery is proposed.