Optimization of piezoelectric actuator configuration on a flexible fin for vibration control using genetic algorithms

An efficient solution to slow crack growth caused by buffet-induced vibration of vertical tails on twin-tail fighter airplanes is to use piezoelectric actuators and sensors to create an adaptive structure that actively reduces the buffeting. The optimization of the sensor and actuator configuration is critical to ensure that the structure will be effective in reducing the vibration for the anticipated loading conditions.; This thesis uses genetic algorithms to solve two optimization problems for vibration control of the first three modes of the fin. The first problem optimizes the position of a single pair of piezoelectric actuators on the fin. The second problem optimizes the activation of a pre-determined number of actuator pairs. The fitness functions for optimization are determined from the Frequency Response Functions (FRFs) measured at an accelerometer for the activation of each possible actuator. Individual modal and multi-modal acceleration and displacement vibration control are considered. The advantage of this method lies in the decoupling of the fitness function formulation from the optimization. In comparison to previous approaches, this allows optimization on much more complex geometries where the derivation of an analytical fitness function is prohibitive or impossible.; The optimization results obtained through simulation are verified through a comparison with results obtained from an experimental model of the fin. The agreement between results from simulation and experiment demonstrates the validity of the optimizations.