L2M NSERC - Deployable Perforated Shellular Metamaterials

在汽车和运输行业中，冲击主要通过一种或多种机制来处理;例如，通过材料变形，摩擦和/或粘弹性，以及力矩传递。汽车保险杠或自行车、足球和曲棍球头盔等安全装置通常包含塑料盖，该塑料盖将冲击载荷传递到溃缩区的泡沫，在溃缩区，冲击被泡沫和其他附件元件吸收，这些附件元件经历永久变形以平稳地减速载荷并减少个人经历的力。高速公路护栏也是如此，其冲击通过金属围栏的塑性变形吸收。在这项研究中，我们打算通过解决其一些缺点来制造下一代这些安全元件，这些缺点包括大多数是一次性使用的，因此在冲击事件发生后必须更换，在不同强度和载荷方向下的能量吸收方面具有非常有限的可编程性，并且体积大/重。我们提出的可持续解决方案是可以实现的，通过将顺利地吸收冲击能量通过可逆的弹性变形穿孔shellulars。在冲击下，所开发的轻质多稳态超材料通过将其存储为应变能来吸收动能，快速恢复机制将能量突然转化为微结构振动并最终转化为热量，并在经历自接触时通过摩擦耗散。这些机制的综合性能可以超越传统的能量吸收方法，并允许开发具有所需特性的紧凑/轻质缓冲器，用于替代负载/保护场景，以更好地保护行人/个人和汽车。

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.