ACTIVE VIBRATION CONTROL IN FINITE PLATES USING A STRUCTURAL POWER-FLOW APPROACH

This paper proposes a strategy for the active control of flexural vibr ation in plates. The proposed strategy consists of minimizing the powe r flow across a closed path encircling the perturbation and the contro l actuators. This approach is equivalent to active noise control based on the far-field power over a closed volume, where the disturbance so urce location is assumed to be known. A frequency-domain adaptive cont rol scheme has been developed aiming at the attenuation of steady-stat e, periodic vibrations. It is assumed that the location of the perturb ation is known. The proposed strategy is investigated using a numerica lly simulated example consisting of a rectangular plate excited by a p erturbation force. Some of the main issues concerning the implementati on of a frequency-domain adaptive controller are investigated. The exp ression of the gradient of the power flowing in or out of a region enc ircling the perturbation force and the control actuators is derived. T he convergence properties of the adaptive scheme are investigated usin g an off-line simulation in the frequency domain. It is shown that the power flow control can result in significant vibration reduction, whi ch is the ultimate goal.