Consistent linearization in elasto-plastic shell analysis

The present paper is directed towards elasto-plastic large deformation analysis of thin shells based on the concept of degenerated solids. The main aspect of the paper is the derivation of an efficient computational strategy placing emphasis on consistent elasto-plastic tangent moduli and stress integration with the radial return method under the restriction of 'zero normal stress condition' in thickness direction. The advantageous performance of the standard Newton iteration using a consistent tangent stiffness matrix is compared to the classical scheme with an iteration matrix based on the infinitesimal elasto-plastic constitutive tensor. Several numerical examples also demonstrate the effectiveness of the standard Newton iteration with respect to modified and quasi-Newton methods like BFGS and others.