Optimization of Smart Beams for Maximum Modal Electromechanical Coupling Using Genetic Algorithms

Abstract

In this article, the piezoelectric coverage area of a shear deformable cantilever beam is optimized for maximum modal electromechanical coupling coefficient. A discrete layer finite element model with piezoelectric capability is implemented to solve the free vibration problem under open-circuit and short-circuit electric boundary conditions. A binary-coded genetic algorithm was used to carry out the optimization. The piezoelectric coverage locations are found to be dependent upon the mode of vibration, which is primarily due to charge cancelation at higher modes. Optimal distribution tends to cover part of the beam experiencing maximum bending. It is shown that the type of base beam material has negligible effect on the optimum locations of the piezoelectric material. Furthermore, an optimum ratio of piezoelectric-to-beam thickness exists for the first three modes.