Active vibration control of smart structures bonded with discrete piezoelectric sensors and actuators located optimally using a reduced genetic algorithm

International Conference on Smart Materials & Structures

June 15 -17, 2015 Las Vegas, USA

Daraji A H

Posters-Accepted Abstracts: J Material Sci Eng

Abstract :

Demand for the development of mechanical structures with high specific strength has increased among industrial companies to build lightweight aerospace structures, tall buildings and long bridges. The objectives of the construction of such structures are to optimize loading capacity, energy consumption and material costs. However, these structures are associated with complicated vibration problems. Traditionally, vibration has been reduced passively by adding mass, damping and stiffness. However, this method leads to increased weight, low response and sensing to low vibration energy. The alternative is active vibration control, in which vibration is measured using sensors and opposed by forces generated by actuators, with a control system linking the two. Piezoelectric sensors and actuators have been investigated in terms of their size, number and location on structures to optimize vibration attenuation. Arbitrarily placing discrete sensors and actuators on a structure leads to weak vibration suppression, whereas more suitable placement using optimization methods such as genetic algorithms can give very effective results. However, for a small structure discretized to one hundred elements optimized for ten sensor/actuator pairs gives 1.73Ã?(10)^13 candidate solutions with many local optima but only one global optimal solution. This research has proven that the optimal distribution for symmetrical dynamic stiffened and unstiffened structures is also symmetric. This symmetry is exploited in genetic algorithm placement strategy by a development of half and quarter chromosomes which reduce the optimization problem by more than 99%. This reduction gives high impact by solving large smart structures to find the global optimal configuration of discrete piezoelectric sensors and actuators with high computational efficiency.