Elastic metamaterials with gradings and their structural applications

Graded designs allowing a progressive wave manipulation have been a cornerstone for the design of functional structures. Either based on local resonance, Bragg scattering or a mix of both, the performance of graded meta go much beyond the so-called bandgap, the original hallmark of elastic metamaterials. I will present different applications where elastic metamaterials featuring graded design have been studied and exploited for different purposes and scales. After introducing early proposals with EM and acoustic waves, applications on graded resonant metasurfaces will be showcased. These include both fundamental laboratory scale experiments but also civil and mechanical engineering-oriented applications for vibration energy harvesting and vibration suppression. I will then show the latest experimental efforts in modeling, optimising and 3D printing lightweight frame-based panels for structural engineering applications. These frames combine lightweight, bioinspired shapes with graded resonant elements and represent a promising design model for reimaging the design of structural members such as trusses, beams and shells integrating vibration control and application in structural engineering and architecture.