The development of an optimization procedure for the design of intelligent structures

Abstract

Intelligent structures are structures which can actively react to an unpredictable environmental disturbance in a controlled manner. Piezoelectric materials are an excellent choice for the development of sensors and actuators for these structures due to their special properties. It is important to locate these discrete actuators optimally on the structure in order to achieve the most efficient implementation of their special properties. It is also necessary to design the structure to be controlled for optimum performance. This leads to a combined problem which includes the discrete actuator location problem and the continuous optimization problem involving control and structure interaction. A multiobjective optimization technique is used to formulate the problem. Optimum piezoelectric actuator thicknesses for the static case are determined for the active piezoelectric elements development in this work. An optimization procedure is then presented which includes actuator locations, vibration reduction, power consumption, minimization of dissipated energy and maximization of the natural frequency as design objectives. The procedure is demonstrated through a cantilever beam problem. Results obtained indicate that improved structural and control performance can be obtained with only a few optimally placed actuators.