On the consistency of finite element models in thermoelastic analysis

✍ Scribed by Stefano de Miranda; Francesco Ubertini

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 216 KB
• Volume: 190
• Category: Article
• ISSN: 0045-7825
• DOI: 10.1016/s0045-7825(00)00244-9

✦ Synopsis

In thermoelastic analysis, compatible ®nite elements may predict oscillating stresses if the temperature distribution is not coherent with the element strain coming from the assumed displacement approximation. Modelling the stress ®eld as an independent variable could be a viable alternative to avoid these spurious outcomes. To this purpose, the behavior of mixed, hybrid stress and equilibrium ®nite element models in the presence of initial strains due to temperature is investigated and compared with the usually employed displacement approach. The consistency requirement for each model is established and the spurious outcomes due to inconsistent temperature ®elds are discussed, examining also the eects of element geometry distortions. The analysis, illustrated through some numerical tests, shows that a direct approximation for the stress ®eld can eliminate, or at least reduce, the generation of spurious stress modes, although this is not a priori guaranteed by a mixed approach.