3D Printed Metamaterials for Energy Absorption in Motorsport Applications

In this study, various 3D printed metamaterials are investigated for application in energy absorbing structures in motorsports. Impact attenuating structures are used to decelerate vehicles and protect drivers in the event of a crash. Additive manufacturing enables complex plastic structures which can facilitate improved angular resistance and reduced weight and cost compared with traditional approaches. Metamaterials were 3D printed from PLA using commercially available equipment and include gyroid structures, a novel reinforced gyroid design and a lattice designed using finite-element analysis-based topology optimization. Compression testing was used to measure stress-strain response, compressive modulus, and energy absorption. This demonstrated gyroids and reinforced gyroids have ideal compressive behavior for high energy absorption under impact. The topology optimized metamaterial was found unsuitable for this application due to its high stiffness, revealing a weakness in traditional topology optimization approaches which are not catered to maximize energy absorption. The reinforced gyroid demonstrated the highest specific energy absorption and was used to manufacture an impact attenuator which demonstrated the potential to safely stop a hypothetical 300 kg vehicle crash. This work supports that gyroid-based structures can reduce weight, volume and cost over current materials in all motorsport categories, with improved safety from oblique crashes.