| The vibration of rotating beams is attenuated using a new class of Active Constrained Layer Damping (ACLD) treatment and a new class of a distributed piezoelectric sensor bounded with the beam. The ACLD treatment consists of two piezoelectric film layers and a visco-elastic damping layer, which is sandwiched between these two piezoelectric layers. The three-layer composite ACLD when bonded to the beam acts as a SMART constraining layer damping treatment with build-in sensing and actuation capabilities. With such capabilities, the shear deformation of the visco-elastic damping layer can be controlled and actively tuned to the response of the rotating beam in order to enhance the energy dissipation mechanism and improve the vibration damping characteristics.; The dynamics of a rotating beam, treated with ACLD treatment and distributed sensor are described with a finite element model. The model accounts for the interaction between the rotating beam, the piezoelectric sensor/actuator, the visco-elastic damping layer and an appropriate control law. The model provides a means for predicting the damping characteristics of the ACLD at different setting angles and controller gains. The experimental performances are presented to show the effectiveness of the ACLD treatment. Comparisons are also presented with the performance of conventional passive constrained layer damping (PCLD). These results clearly demonstrate the attenuation capabilities of the Actively-controlled Constrained Layer Damping and suggest its potential in suppressing the vibration of practical systems, such as helicopter rotor blades. |
