Comparative Study Of Constitutive And Finite Element Formulations For Large Strain Elastoplasticity

Abstract

This paper presents a comparative study of the different formulations used in research groups
in Li`ege and Mendoza, for the modelling of large plastic deformations. The comparison focused on a few
academic standardized problems. We analysed both the constitutive formulation (strain-stress relations)
and the finite element formulation (discretized mechanical balance equations).
In particular, we compared two constitutive formulations, both hyperelastic, but resulting from different
theoretical approaches. We also compared different types of finite elements (4-noded quadrangles
and 6-noded triangles), in axisymmetric and plane strain settings.
These comparisons show that both approaches yield very similar results. Computations also show
that models based on 6-noded triangles give good results. The only limitation suggested by the results
obtained is that triangles appear to be more sensitive to large distorsions than quadrangles.