L2M NSERC - Deployable Perforated Shellular Metamaterials

在汽车和交通运输行业，影响主要是处理一个或多个机制；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、自行车、足球和曲棍球头盔等安全装置通常包含一个塑料罩，将冲击载荷转移到褶皱区域的泡沫上，在那里，冲击被泡沫和其他附属元件吸收，这些元件通过永久变形来平稳地减速载荷并减少个人承受的力。高速公路护栏也是如此，金属护栏的塑性变形吸收了冲击。在这项研究中，我们打算通过解决这些安全元件的一些缺点来制造下一代安全元件，比如它们大多是一次性使用的，因此在撞击事件发生后必须更换，在不同强度和方向的载荷下，它们在能量吸收方面具有非常有限的可编程性，体积庞大/沉重。我们提出的可持续解决方案是通过加入穿孔壳，通过可逆的弹性变形平滑地吸收冲击能量。所开发的轻质多稳态超材料在受到冲击时，通过将动能存储为应变能、突然将能量转化为微建筑振动并最终转化为热量的弹回机制吸收动能，并在经历自接触时通过摩擦消散动能。这些机制的综合性能可以超越传统的能量吸收方法，并允许开发具有替代负载/保护场景所需特性的紧凑/轻量级缓冲器，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.