Zig-Zag effect without degrees of freedom in linear and non linear analysis of laminated plates and shells

Without adding new degrees of freedom, this paper presents a new finite element formulation that combines three important ingredients for precise analysis of displacements and transverse stresses in laminated shells and plates, namely: (i) Presence of Zig-Zag effect, (ii) regularization of transverse stresses in order to guaranty their continuity and (iii) cinematically exact description in FEM nonlinear geometric formulation. The accuracy of the proposed formulation in both displacements and stresses will be proven by comparing results with linear elastic benchmarks of literature. Furthermore, the possibilities of the formulation are shown by solving an extreme geometric nonlinear problem of orthotropic laminated shells, considering results in displacements and stresses.