L2M NSERC - Deployable Perforated Shellular Metamaterials

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In the automotive and transportation industry, impact is mainly dealt with one or multiple of mechanisms; for example, through material deformation, friction and/or viscoelasticity, and moment transfer. Safety devices like car bumpers or bike, football, and hockey helmets usually contain a plastic cover that transfers the impact load to a foam in the crumple zone, where the impact gets absorbed by the foam and other accessory elements that go through permanent deformation to smoothly decelerate the load and reduce the force that individuals experience. Same is true about highway guardrails where the impact is absorbed by plastic deformation of the metallic fence.In this study, we intend to make the next generation of these safety elements by addressing some of their shortcomings like being mostly single-use and therefore they must be replaced after the impact incident, possessing a very limited programmability in terms of energy absorption under different intensity and direction of loads, and being bulky/heavy. Our proposed sustainable solution is achievable by incorporating perforated shellulars that smoothly absorb the impact energy through reversible elastic deformation. Under an impact, the developed lightweight multistable metamaterials absorb the kinetic energy through storing it as strain energy, snap-back mechanism that abruptly transforms energy into microarchitectural vibration and eventually to heat, and dissipating it through friction when experiencing self-contact. The combined performance from these mechanisms can surpass the traditional methods of energy absorption and allows developing compact/lightweight buffers with desired traits for alternative loading/protection scenarios to better protect both pedestrian/individual and the car.