engleski

Smart structures for noise and vibration control

Smart structures are such structural systems whose geometric and inherent structural properties can be beneficially changed to meet application requirements, either through a command or automatically - in response to external stimulations. Techniques have been developed which can be used to modify geometry, stiffness, damping, and isolation properties of active structures. The emergence of active structures came through the new developments in sensing and actuating methods. Most widely used sensing and actuating members are: piezoelectric, electrostrictive and magnetostrictive materials, electrorheological and magnetorheorogical fluids, and shape-memory alloys. In this research project noise transmissibility and vibration of a smart double-wall structure is decreased by generating active damping. Piezoelectric sensors and electrodynamic actuators are embedded into the structure and used to establish decentralised direct velocity feedback control. The complexity of the control system is reduced and the robustness increased by the use of decentralized, mutually independent sensor-actuator pairs. When the smart structure is activated, the sound that is transmitted through it is efficiently reduced. In case of aerospace applications, due to strict weight limitations, smart structures can be an option that puts a question mark over the traditional noise and vibration control solutions.

Smart structures; decentralised control; direct velocity feedback; active damping

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