Influencing the dynamic properties of weakly damped structures through systematic design of linear and non-linear metamaterials

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Periodic loads lead to vibration excitation in technical structures, whereby light and thin components are particularly affected. If the damping is also distributed inhomogeneously, i.e. locally concentrated, wave dynamics occur in the structure between excitation and local damping. Classical means for vibration reduction are often no longer sufficient in this case. A promising approach to influence the dynamics of such structures is the use of metamaterials. Metamaterials are periodically arranged substructures which are themselves able to oscillate and which influence not only modal parameters but also frequency ranges of wave propagation. Within the scope of this project, metamaterials will be systematically designed, intentionally including nonlinear substructures. For this purpose, methods of nonlinear dynamics are adapted and transferred. The objective is a general design using finite element models with complex boundary conditions to describe the periodic substructures. For validation, linear and nonlinear beam structures with metamaterial are produced and experimentally investigated. In order to be able to study also reproducible travelling waves, a combination of piezo elements and acoustic black holes will be analyzed and used as local energy sinks. With the knowledge gained, a systematic design of nonlinear amplitude-dependent metastructures will be possible for an extended influence on structural dynamic properties.