Yousefi-Koma A., Haddadi S.

In this paper, superposition method is applied to piezoelectric actuator effects on a flexible structure. One of the important issues in smart structures control is the configuration and grouping of actuators. Based on a desired modal control, various configurations and grouping of actuators may be selected. Thus, it is important to know how to combine the actuators effects in simulation before fabricating the real model. A series of signal actuation runs, either in simulation or experiment, can be utilized to predict the performance of a specific group of actuators. The physical model considered in this study is a flexible Aluminum fin fixed at the base. The condition in which the superposition method is valid is investigated. Frequency Response Function (FRF) in the range of 0-100 Hz consisting of the first three modes is obtained for the four different actuator locations. The FRF of the all actuators together as a group is also derived. The dynamic response of the smart structure with superposition of the four individual responses caused by single actuators is then compared with the response of the structure under actuation of all actuators simultaneously. Results show that the proposed superposition method is valid in smart structures actuation and control. The idea of superposition is very cost effective as it does not require iterative work to find the optimum actuator configuration. Once all the actuators are dynamically identified (i.e. System Identification), the selection of the desired piezoactuator group is done offline, without experimental iteration.