Extension of the 'solid-shell' concept for application to large elastic and large elastoplastic deformations

In the present contribution we extend a previously proposed so-called solid -shell concept which incorporates only displacement degrees of freedom to t he simulation of large elastic and large elastoplastic deformations of shel ls. Therefore, the modifications necessary for hyper-elastic or elastoplast ic material laws are discussed. These modifications concern the right Cauch y-Green tensor for large elastic deformations, respectively, the deformatio n gradient for elastoplasticity which then are consistent to the modified G reen-Lagrange strains that are necessary for transverse shear and membrane locking free solid-shell element formulations. However, in addition to the locking mentioned above especially in the range of plasticity incompressibility locking becomes important. Thus, the secon d major aspect of this contribution is the discussion of several ways to av oid incompressibility locking also including the investigation of eigenmode s. Finally, a selective reduced integration scheme with reduced integration for the volumetric term is employed and described in detail, although it i s limited to material laws which allow the decomposition into a volumetric and a deviatoric part. Some numerical examples show the range of applicatio n for the proposed elements. Copyright (C) 2000 John Wiley & Sons, Ltd.