Lee Min Kyung, Kim Yoon Young
Department of Mechanical and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Korea.
Institute of Advanced Machine and Design, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul, 151-744, Korea.
Sci Rep. 2016 Feb 10;6:20731. doi: 10.1038/srep20731.
Metamaterial cloaks control the propagation of waves to make an object invisible or insensible. To manipulate elastic waves in space, a metamaterial cloak is typically embedded in a base system that includes or surrounds a target object. The embedding is undesirable because it structurally weakens or permanently alters the base system. In this study, we propose a new add-on metamaterial elastic cloak that can be placed over and mechanically coupled with a base structure without embedding. We designed an add-on type annular metamaterial plate cloak through conformal mapping, fabricated it and performed cloaking experiments in a thin-plate with a hole. Experiments were performed in a thin plate by using the lowest symmetric Lamb wave centered at 100 kHz. As a means to check the cloaking performance of the add-on elastic plate cloak, possibly as a temporary stress reliever or a so-called "stress bandage", the degree of stress concentration mitigation and the recovery from the perturbed wave field due to a hole were investigated.
超材料隐身衣控制波的传播以使物体不可见或不被察觉。为了在空间中操控弹性波，超材料隐身衣通常嵌入包含或围绕目标物体的基础系统中。这种嵌入是不可取的，因为它会在结构上削弱或永久改变基础系统。在本研究中，我们提出了一种新型附加式超材料弹性隐身衣，它可以放置在基础结构之上并与其进行机械耦合，而无需嵌入。我们通过保角映射设计了一种附加式环形超材料平板隐身衣，制造了它，并在带有孔洞的薄板中进行了隐身实验。实验在薄板中使用以100kHz为中心的最低对称兰姆波进行。作为检查附加式弹性平板隐身衣隐身性能的一种手段，可能作为一种临时应力消除器或所谓的“应力绷带”，研究了应力集中缓解程度以及由于孔洞导致的扰动波场的恢复情况。
