Analysis of thickness locking in classical, refined and mixed theories for layered shells

This paper is a sequel of the article: ‘Analysis of Thickness Locking in Classical, Refined and Mixed Multilayered Plate Theories’, Composite Structures, available online 9th February 2007. The analysis of thickness locking (TL) mechanism, (which is a plate/shell-theory mechanism, caused by the use of simplified kinematic assumptions) is herein extended to shell geometries. Bending problems have been analyzed for isotropic, one-layered and multilayered shells. TL has been investigated for a large variety of shell theories: thin shell theory, first order shear deformation theory, higher order theories, mixed theories and layer-wise theories. The unified formulation has been used to implement the whole considered shell modelings. Analytical closed form solutions have been considered. A comprehensive numerical investigation has been performed. The conclusions have been acquired: TL appears if and only if transverse normal strains ϵzz are assumed constant; the use of LW models introduces benefits vs TL; mixed methods do not make any ‘relevant’ improvements with respect to TL; TL does not depend on geometrical curvature parameters.