A comparison of zigzag functions for the bending, vibration and buckling analysis of multilayered composite and sandwich plates

In the framework of the Zigzag theories, an important role is played by the zigzag function. In the open literature, two kind of zigzag functions exist. A comparison of the advantages in adopting one zigzag function rather than the other is compulsory. In this work, with a general formalism, a displacement-based model wherein the First Order Shear Deformation (FSDT) kinematic is enriched by adding a zigzag contribution only to the inplane displacements description, is developed. By selecting the zigzag function, two models arise from the general formulation. Comparison on the response predictive capabilities ensured by the two zigzag functions, is made. Results pertaining the elastostatic deformation, free vibrations and buckling load problems of square sandwich plates subjected to several load and boundary conditions are compared with exact Elasticity solutions, when available, or high-fidelity FE model.