Vibration control of composite plates under random loading using piezoelectric material

Abstract A study of the use of H∞ control design to suppress the vibrations of composite plates with embedded piezoelectric actuators under random loading is presented. The finite element method is employed to obtain the dynamic equations of plate vibration. The finite element model includes fully coupled structural and electrical nodal degrees of freedom. The modal reduction method using the structural modes is adopted to reduce the finite element equations into a set of modal equations with fewer degrees of freedom. The modal equations are then employed for controller design and time domain simulation. The results of the modal convergence studies of the closed-loop systems show that the truncated modes, which are neglected in the control design, deteriorate the controller performance and affect the optimal location and size of the actuator. The vibrations of plates subjected to off-resonant narrow-band excitations cannot be suppressed significantly. The controller shaped with an extra weight function for mitigating measurement noise gives better vibration reduction performance.