Séminaire Lamcos : Dislocated transducer methodology for the nonreciprocal transmission of sound and vibration, Neven ALUJEVIC, University of Zagreb

This talk presents theoretical and experimental studies of active acoustic metamaterial (AMM) cells for nonreciprocal transmission of sound and vibration. Such active AMMs promise to achieve superb sound and vibration isolation at low frequencies, which is normally difficult with traditional materials and measures. Furthermore, active AMM could exhibit acoustic opacity in one direction while preserving acoustic transparency in the opposite direction. Feedback control systems with dislocated sensor-actuator pairs are used to induce the nonreciprocity. The principle of operation of the active control system is first elaborated through simple lumped-parameter models. It is the shown theoretically and experimentally that the dislocated transducer methodology induces a broad frequency band nonreciprocal vibration transmission and that the active control system can be made stable regardless the transducer dislocation. The nonreciprocal transmission of sound is studied using a dedicated theoretical model. The model