Determination of material constants of piezoceramics using genetic algorithm

Abstract

This study seeks to accurately determine the piezoelectric material constants of piezoceramic disks from the resonant frequencies of the disks using a genetic algorithm programmed according to the principles of plate theory. Mindlin's plate theory is judged to be most suitable for approximating the relationship between the in-plane and out-of-plane resonant frequencies and the material constants of a disk-shaped piezoceramic thick plate, which was programmed into a genetic algorithm in order to obtain all relevant piezoelectric material constants from measured resonant frequencies of sample piezoceramic disks through inverse calculation. To verify the accuracy of the material constants, finite element method was employed to derive the theoretical resonant frequencies along with the corresponding mode shapes, which were then compared with the actual resonant frequencies measured using amplitude-fluctuation electronic speckle pattern interferometry. The comparison shows that the genetic algorithm can successfully determine all desired material constants of piezoceramic disks from the measured resonant frequencies in a single operation, and that the resonant frequency values modeled using the constants more accurately correspond to the experimentally measured frequencies than those derived from material constants obtained using conventional methods.