Component-Wise Modelling of Core and Skin in Sandwich Structures Using a Single Refined Beam Finite Element

This study presents an efficient component-wise representation of both core and skin components of a sandwich structure using one-dimensional (1D) finite elements. The approach considers a core made of hexagonal cells and is based on the Carrera Unified Formulation (CUF). CUF enables the modeling of complex structures as 1D beam models by accurately defining their cross-sectional geometry using high-order Lagrange polynomials. This method ensures the exact representation of both geometry and deformation characteristics. Unlike traditional 1D finite elements definition, in this study the structural beam axis is aligned with the thickness of the sandwich panel, while the cross-section extends across its width. In this way, both core and skins are described with their actual geometry, without the need of adopting any homogenization. Static linear analyses demonstrate that the proposed CUF-based advanced 1D modeling achieves structural response accuracy comparable to that of three-dimensional (3D) FEM models implemented in Abaqus. Notably, this is accomplished with a significant reduction in the degrees of freedom, highlighting the computational efficiency of CUF framework. These results underline the potential of advanced CUF-based 1D modeling for applications involving sandwich structures with any core geometry.