Abstract
Composite sandwich structures incorporating foams or honeycombs as core materials have been widely researched and employed in various fields. Traditional cores often face limitations such as poor impact resistance, sustainability issues, and the inability to provide graded properties along their thickness. This paper explores the production and mechanical analysis of hemp bi-grid cores designed for use in sandwich structures, by using an ad-hoc continuous manufacturing process. Both graded cores, with varying fibre content through their thickness and non-graded cores were produced. The mechanical properties of these cores were evaluated under flexural and compressive testing. Additionally, to assess their impact performance in sandwich panels, hybrid panels with CFRP skins were fabricated and subjected to Low Velocity Impact tests. The resulting damage was examined using CT-Scan. The results indicate that the possibility of customising failure modes and tailor energy absorption capabilities of the proposed structures open the way for new, exciting perspectives for the development of innovative sandwich structures, broadening the application of natural fibres in various industrial sectors.