Finite element analysis of periodic and random 2-2 piezocomposite transducers with finite dimensions

A finite size periodic 2-2 composite transducer has been studied using finite element method, and the numerical results are verified by experiments. The focus of this study is on the mode coupling between the thickness resonance and pitch resonance. Such coupling effectively limits the pitch size of the composites preventing them being used in high frequencies. The effects of randomness is also being investigated using finite element analysis. The pitch resonance can be effectively suppressed by introducing 50 to 80% randomness in the structure. Numerical results also show that the decoupling of the thickness resonance and pitch resonance can increase the electromechanical coupling coefficient k/sub t/ for the thickness mode and shifts the thickness resonance frequency.