  This article investigates the large deflection and post-buckling of composite
plates by employing the Carrera Unified Formulation (CUF). As a consequence,
the geometrically nonlinear governing equations and the relevant incremental
equations are derived in terms of fundamental nuclei, which are invariant of
the theory approximation order. By using the Lagrange expansion functions
across the laminate thickness and the classical finite element (FE)
approximation, layer-wise (LW) refined plate models are implemented. The
Newton-Raphson linearization scheme with the path-following method based on the
arc-length constraint is employed to solve geometrically non-linear composite
plate problems. In this study, different composite plates subjected to large
deflections/rotations and post-buckling are analyzed, and the corresponding
equilibrium curves are compared with the results in the available literature or
the traditional FEM-based solutions. The effects of various parameters, such as
stacking sequence, number of layers, loading conditions, and edge conditions
are demonstrated. The accuracy and reliability of the proposed method for
solving the composite plates' geometrically nonlinear problems are verified.
