Crashworthiness of foam filled truncated conical sandwich shells with corrugated cores

Polymeric foam filled truncated metallic conical sandwich shells with corrugated cores were proposed, and their energy absorption characteristics under axial compression were systematically investigated. The types of foam filling include: (i) foam filling inner cavity (FFIC), (ii) foam filling corrugated channel (FFCC), and (iii) foam filling inner cavity and corrugated channel (FFICCC). Test specimens were fabricated by combining the step-by-step molding method with the method of in-situ foam filling. Firstly, the crashworthiness of FFIC, FFCC and FFICCC subjected to axial compression was experimentally characterized. Secondly, numerical simulations with the method of finite elements (FE) were performed, with good agreement achieved between measurements and simulations. Subsequently, based upon the validated FE models, interaction mechanisms between foam filler and metallic shell were explored, and the influences of wall thickness, semi-apical angle and loading speed on energy absorption were quantified. The three different foam filled structures were found to exhibit higher energy absorption than their unfilled counterpart. Particularly, the specific energy absorption (SEA) of the FFCC was higher than that of the unfilled structure, attributed mainly to the participation of all foam fillers in the interaction with metal shells that was rarely found in other types of foam-filled structure.