@article {Cheer:2020:0736-2935:5255, title = "On the potential of a functionally graded acoustic black hole using multi-material additive manufacturing", journal = "INTER-NOISE and NOISE-CON Congress and Conference Proceedings", parent_itemid = "infobike://ince/incecp", publishercode ="ince", year = "2020", volume = "261", number = "1", publication date ="2020-10-12T00:00:00", pages = "5255-5261", itemtype = "ARTICLE", issn = "0736-2935", url = "https://ince.publisher.ingentaconnect.com/content/ince/incecp/2020/00000261/00000001/art00032", author = "Cheer, Jordan and Daley, Steve", abstract = "Acoustic Black Holes (ABHs) have been demonstrated as an effective and particularly lightweight passive vibration control solution. They are able to achieve a high level of structural damping with a thin layer of concentrated damping material by introducing a reduction in the structural wave speed. This is generally achieved by introducing a geometrical taper into the structure and the performance is maximised with a long taper that reaches a small tip height. This design approach introduces a potential weakness into the structure and, therefore, this paper explores an alternative method of achieving a reduction in the wave speed. Instead of a geometrical taper, the potential of realising the ABH effect using a functionally graded structural feature that can be achieved through multi-material additive manufacturing is investigated. Requirements on the gradient of the material properties are first investigated and then a design optimisation strategy is presented to enable the practical realisation within the constraints of a commercially available multi-material additive manufacturing process.", }