Biomimetic approaches towards lightweight composite structures for car interior parts

Due to good density specific mechanical properties and low carbon footprint, natural fibre-reinforced plastic composites made from fleeces and felts are frequently used as automotive interior parts. The industry targets further mass reduction. Following a biomimetic technology-pull approach, natural fibre-reinforced polypropylene plates with improved lightweight potential were produced using compression moulding. Best results were obtained for a sandwich structure with thin, unidirectional flax fibre layers surrounding a needle felt based core. It was inspired by the carapace structure of the red-eared slider Trachemys scripta elegans. The lay-up performed well, not only with a high density specific flexural stiffness of 2.33 GPa1/3 cm3/g, strength of 9.46 MPa1/2 cm3/g, and energy dissipation but also through less abrupt failure due to an asymmetric orientation of unidirectional fibres in the two face sheets. Combined with a mass-reduced needle felt as a core, this concept displays a promising and unconventional approach for further mass reduced, sustainable interior panels used as non-visible and visible design elements in the vehicle.