Considerations on higher-order finite elements for multilayered plates based on a Unified Formulation

In this work, a numerical assessment of a series of multilayered finite plate elements is proposed. The finite elements are derived within the “Unified Formulation”, a technique developed by Carrera for an accurate modeling of laminates. The Unified Formulation affords an implementation-friendly possibility to derive a large number of two-dimensional, axiomatic models for plates and shells. An accurate model for multilayered components naturally involves transverse shear and normal stresses, as well as higher-order displacement assumptions in thickness direction. The aim of this work is to give a first insight of the numerical properties of finite elements relying on these formulations. Some considerations concerning the numerical difficulties associated to thickness locking phenomena are presented. A detailed numerical analysis is performed to study the shear locking phenomenon. For the selected case study, once the latter spurious stiffening effect is suppressed with classical or advanced numerical techniques, the resulting elements are shown to behave robustly and accurately.