Active constrained layer damping of plate vibrations: a numericaland experimental study of modal controllers

Abstract

In this paper the authors address the problem of suppressing thevibrations of a clamped-clamped plate using an active constrained layerdamping treatment. This treatment involves adding viscoelastic and metallicconstraining layers to the host plate and then augmenting this arrangementwith an active feedback scheme using piezoelectric actuators. The basis of thecontrol strategy is an effective model of the plate together with the passivedamping treatment. The paper summarizes the modelling procedures including thefinite-element formulation, model reduction and model updating. By this meansa low-order model, capable of accounting for the observed behaviour, is developed.Emphasis is placed upon the design and implementation of active modalcontrollers based upon the reduced and updated model. Four actuator/sensorconfigurations are examined in both numerical and experimental studies. It isshown that effective control of the first two modes of vibration (bending andtorsion) can be achieved using only a single actuator and single sensor.However, the most effective configuration involves two actuators and twosensors operating as two independent control channels. It is shown thatthrough suitable design, the active constrained layer damping treatment iscapable of avoiding problems due to spillover effects.