New method of damping structural vibrations based on the acoustic black hole effect

该项目的目的是进行理论和实验研究的新的有效方法的阻尼结构振动的基础上的具体功能的弯曲波的传播和反射的弹性楔形结构的幂律剖面。这种结构的工作原理是基于最近发现的一类新的“陷波”现象，这种现象可能发生在弹性楔形物中，弹性楔形物的横截面由楔形物局部厚度d与距其边缘的距离x之间的幂律关系描述。特别地，对于功率m = 2和更高-在自由楔形物中，以及对于功率m = 5/3和更高-在浸没楔形物中，入射弯曲波可以在边缘附近被捕获，因此它们永远不会反射回来，即上述结构实现了弯曲波的声学“黑洞”。与附接到边缘的薄吸收层的窄条相结合，这种楔形结构即使在非理想幂律轮廓的真实的楔形物的情况下也可以提供非常低的反射，从而实现阻尼共振弯曲振动的非常有效的方式。在拟议的项目中，旨在进一步开发和研究基于声学黑洞效应的阻尼结构振动的新方法。计划在理论和实验上详细研究几种有前途的声学黑洞结构。在拟议的项目中，重点将放在迄今尚未研究的所谓二维黑洞上。该项目的结果将导致开发新的非传统和非常有效的阻尼结构振动的方法，这些方法甚至可以用于不同的工程应用。

The aim of the proposed project is to carry out theoretical and experimental investigations of the new efficient method of damping structural vibrations based on the specific features of flexural wave propagation and reflection in elastic wedge-like structures of power-law profile. The principle of operation of such structures is based on the recently discovered new class of 'wave trapping' phenomena that may take place in elastic wedges having cross sections described by a power law relationship between the wedge local thickness d and the distance from its edge x. In particular, for powers m = 2 and higher - in free wedges, and for powers m = 5/3 and higher - in immersed wedges, the incident flexural waves can be captured near the edges and therefore they never reflect back, i.e. the above structures materialise acoustic 'black holes' for flexural waves. In combination with narrow strips of thin absorbing layers attached to the edges, such wedge-like structures can provide very low reflections even in the case of real wedges of non-ideal power-law profile, thus implementing very efficient way of damping resonant flexural vibrations. In the proposed project, it is intended to further develop and investigate the proposed new method of damping structural vibrations based on the acoustic black hole effect. It is planned that several promising configurations of structures with acoustic black holes will be investigated in detail both theoretically and experimentally. The emphasis in the proposed project will be made on the so-called two-dimensional black holes that have not been investigated so far. The results of the project will lead to the development of new non-traditional and very efficient ways of damping structural vibrations that eventially could be used in different engineering applications.