A mixed cubic zigzag model for multilayered composite and sandwich plates including transverse normal deformability

A new Mixed Cubic Zigzag Theory (CZT(m)) has been developed via the Reissner Mixed Variational Theorem. The assumed kinematic field postulates an in-plane displacement components piecewise cubic along the thickness and a smeared parabolic through-the-thickness distribution for the transverse displacement. The assumed transverse shear stresses profile derives from integration of the three-dimensional equilibrium equations whereas the normal stress pattern is assumed smeared cubic along the laminate thickness. The entire formulation is here developed and the governing equations derived are used to solve the bending problem of a rectangular simply-supported cross-ply plate subjected to a bisinusoidal transverse load. In order to assess the predictive capabilities of the CZT(m) model, results are compared with the exact three-dimensional Elasticity solution.