Deliberate introduction of acoustic radiation damping using locally resonant materials

• Applicant: Professor Dr.-Ing. Steffen Marburg
• Subject Area: Mechanics ; Acoustics
• Term: from 2016 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 314928016

Many lightweight structures are stiff and weakly damped. This observation holds for a number of musical instruments and some submerged structures too. These structures have in common that acoustic radiation damping may be of a similar or even higher magnitude than other damping mechanisms. This proposal is directed to investigate such cases and to provide mathematical formulations which allow to consider acoustic radiation damping in a purely structural model although the actual physics would require a coupled structural acoustic model. However, mathematically, the structural acoustic model can be reduced to a structural one where the Schur complement represents the entire fluid behavior. This project investigates acoustic radiation damping quantitatively and aims at the development of a mathematical model to consider acoustic radiation damping without solution of the acoustic radiation problem. Beside the actual radiation damping, the quantitative estimation includes investigation of numerical damping occurring in acoustic BEM formulations and fluid damping which may become relevant at high frequencies. The uncoupled structural model may consider radiation damping either as a modal damping or as a viscoelastic bedding. Finally, structures which utilize acoustic radiation damping will be developed and investigated.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1897: Calm, Smooth and Smart - Novel Approaches for Influencing Vibrations by Means of Deliberately Introduced Dissipation