Advanced finite element approaches for the 2D analysis of multilayered and sandwich beams

This work presents a new critical overview and a numerical assessment of some advanced Finite Element (FE) approaches for the analysis of multilayered composite and sandwich beams. Firstly, the fundamental hypotheses behind the Timoshenko Beam Theory (TBT) and the Refined Zigzag Theory (RZT) are addressed, and corresponding low-order simple and efficient C0 two-noded beam elements are recalled for 2D cylindrical bending problems. Additionally, two novel advanced FE techniques are employed for 2D bending analysis, i.e. the Multi-Scale (MS) analysis and the Beam-Like Reduced Order Model (BLROM). The proposed FE models are used to investigate the static cylindrical bending response of multilayered composite and sandwich beams under different boundary conditions. The results demonstrate the superior predictive capabilities of the RZT, MS and BLROM models compared to the TBT one. Furthermore, despite having the same kinematics as the TBT, the MS and BLROM models guarantee enhancements in axial strain and transverse shear stress distributions. In addition, the RZT confirms its superior accuracy in predicting both transverse displacements and strains across the laminate thickness. Depending on their accuracy, the RZT, MS and BLROM models are computationally more advantageous than other expensive high-fidelity FE approaches and excellent candidates for the 2D static analysis of multilayered beams.