CONSISTENT DISCRETIZATION OF THICKNESS STRAINS IN THIN SHELLS INCLUDING 3D-MATERIAL MODELS

Following an idea by Büchter et al. (1994), the normal strain in the thickness direction of shells with inextensible directors is accounted for by the EAS-method, in order to enforce for arbitrary 3D-material models the zero normal stress-condition in the average sense. In the present paper a polynomial expansion of the normal strain interpolation in the thickness direction including the constant term is proposed. This extension is consistent with Simo and Rifai (1990). The proposed method is also suitable to analyse plane stress problems with arbitrary 3D-material models. Copyright # 1999 John Wiley & Sons, Ltd. KEY WORDS EAS-method; thickness strains; inextensible shell director; consistent strain interpolation 1