A note on enhanced strain methods for large deformations Original Research Article

Enhanced strain elements have been applied to simulate geometrically and materially non-linear problems. Their main advantage is due to the fact that they perform very good in the incompressible limit as well as in bending situations. However, in compressive deformation states these elements depict stability modes which are associated with hour-glass forms and thus denote a rank deficiency for such deformations. In this paper the appearance of these modes will be investigated analytically by means of a simple representative example.