Vibration Control Of Active And Passive Hybrid Damping Structure

Recently, the research of hybrid active-passive damping to vibration control has been one of focus in the field of vibration control. The investigation of ACLD treatments has shown it to be an effective method of vibration suppression. In this work, ACLD and two hybrid configurations are investigated by separating the passive and active elements. In the first variation, the active element is underneath PCLD. The other variation allows one of the treatments to be placed on the opposite side of the beam. A comparison will be made with PCLD, ACLD and two hybrid configurations(ACUPCLD and ACOPCLD). Hamilton's Principle are used to obtain equations of motion, which are discretized using finite element method. The frequency dependent damping of viscoelastic layer is modeled using the Golla-Hughes-McTavish (GHM) method and the system is analyzed in the time domain. GHM increases the size of the original system by adding fictitious dissipation coordinates that account for the frequency dependent damping. An Optimal Hankel norm approximation model reduction method is used to reduce the equations of motion to lower order size. It is shown that the method is steady, efficient by numerical emulating. Firstly, The influence of viscoelastic layer thickness and material properties, piezoelectric actuator layers thickness on the vibration suppression are investigated. It is shown that vibration suppression efficiency of these kind of treatments depend much more on the viscoelastic layer thickness, material properties and the piezoelectric layer thickness. Secondly, A linear quadratic regulator and output feedback are used to actively control vibration. It is shown that placing the active element on the opposite side of PCLD or underneath PCLD is capable of vibration suppression with lower control effort and more inherent damping. LQR provides the best control, since it assumes all states are available for feedback. Usually only select states are available and output feedback is used. It is shown that output feedback, while not as effective as full state feedback, is still able to damp vibration. Thirdly, virtual vibration measurement and control instrument is developed using Lab VIEW and homemade DAQ, then experiments are performed to validate the conclusion of analysis results.