论文标题
振动弹性板中多个相互作用空隙的全向抗弯曲的隐形性
Omnidirectional flexural invisibility of multiple interacting voids in vibrating elastic plates
论文作者
论文摘要
在弹性方面，包含包含或空隙的掩饰的设计使其存在不受器的振动场，因此要实现其隐形，这是一个彻底的分析，但仍未受到挑战，机械问题。最初以电磁和光学为基础开发的“掩饰转换”概念并不直接适用于弹性波，显示出复杂的矢量性质。因此，到目前为止，所有弹性披肩的例子都涉及复杂的设计和厚厚的涂层皮肤。这些墙壁通常仅适用于频率狭窄范围内的单向传播问题，仅考虑一个颜色的物体。在这里，通过弹性僵硬和质量重新分布实现的基于加固概念的新方法被引入弹性板中的多个空隙。这种简单的技术产生了空隙对极为广泛的频率范围内的弯曲波的隐形性，因此在许多现有的披风技术中都超越了。拟议的设计原理适用于从微观到土木工程规模的机械问题。例如，我们的结果表明了如何设计带有负载的装载建筑物墙，在地震中与同一壁一样振动，但不受限制地进行地震保护的新发现。
In elasticity, the design of a cloaking for an inclusion or a void to leave a vibrational field unperturbed by its presence, so to achieve its invisibility, is a thoroughly analyzed, but still unchallenged, mechanical problem. The 'cloaking transformation' concept, originally developed in electromagnetism and optics, is not directly applicable to elastic waves, displaying a complex vectorial nature. Consequently, all examples of elastic cloaking presented so far involve complex design and thick coating skins. These cloakings often work only for problems of unidirectional propagation, within narrow ranges of frequency, and considering only one colaked object. Here, a new method based on the concept of reinforcement, achieved via elastic stiffening and mass redistribution, is introduced to cloak multiple voids in an elastic plate. This simple technique produces invisibility of the voids to flexural waves within an extremely broad range of frequencies and thus surpassing in many aspects all existing cloaking techniques. The proposed design principle is applicable in mechanical problems ranging from the micro-scale to the scale of civil engineering. For instance, our results show how to design a perforated load-bearing building wall, vibrating during an earthquake exactly as the same wall, but unperforated, a new finding for seismic protection.
