On the Crashworthiness Behaviour of Additive Manufactured Sandwich Panels

This paper explores the advantage introduced, in terms of load dissipation during a crash test, of additive manufactured composite sandwich panels. A numerical investigation has been performed on a small electric bus by comparing the results obtained by explicit crash test simulations with and without composite sandwich panels as shock absorption systems. To assess the crashworthy behaviour of the investigated structures, detailed numerical simulations with 3D formulation based finite element models have been performed within the ABAQUS Explicit FEM environment. The proposed sandwich panels configuration has been obtained by combining carbon reinforced skins with a polymeric core. This kind of hybrid structure has been considered suitable to dissipate large amounts of impact energy both by plasticisation and by fibre and matrix breakage due to the interaction between the ductility of the polymeric core with the brittle behaviour of the CFRP skins. In addition, the proposed sandwich panels are expected to exhibit a considerably high absorbed energy to mass ratio due to use of the additive manufacturing technique to produce the polymeric core. This manufacturing technique allow the definition of complex microstructures, such as lattice microstructures, characterised by significant energy absorption capabilities with a considerable mass reduction. Hence, the research study presented in this paper is aimed to prove that, for the analysed small electric bus configuration, the considered combination of innovative materials and processes can help to develop compact and highly efficient shock absorber sandwich panels capable to reduce both stress and energy distribution on the chassis structure.