Origami-Inspired Cylindrical Structures for Energy Absorption in Aerospace Applications

The current work emphasizes on hybridization of the cylindrical curved crease origami structure with high energy absorbing state-of-the-art cellular lattices mainly, the plate, truss, and hourglass lattices, with a motive to enhance the energy absorption capability of the structure. A novel non-hybridized curved crease cylindrical origami namely star curved and three of its hybridized counterparts, star curved plate (S.C.P), star curved truss (S.C.T) and star curved hourglass (S.C.HG) are proposed in the paper and the effect of hybridization on the energy absorption properties was investigated. Additionally, the deteriorating effect of moisture on the mechanical properties and energy absorption characteristics was emphasized and it was observed that the dried samples outperformed the as-fabricated samples. The structures were designed with the help of CAD software and fabricated via fused filament fabrication (FFF) due to its capability of providing geometrical flexibility and precise control of micro architecture and dimensions using Nylon polymer. The structures were later tested on an Instron compression testing machine to obtain the force-displacement data for further processing. The results substantiate the validity of the hybridization approach as the specific energy absorption of the non-hybridized structure was enhanced from 4 kJ/kg to 6.6 kJ/kg. Moreover, the mechanical properties like peak strength and elastic modulus were remarkably improved from 1.3MPa to 6.5 MPa and 41 MPa to 290MPa respectively. The proposed approach leads to an increase in possibilities for improving the origami-inspired structures in terms of specific energy absorption for situation-specific applications and when incorporated into sandwich panels, the performance of these structures can further be explored.