Finite element analysis and experimental study on 1-3 piezoelectric composites with modified polymer phase

A novel kind of 1-3 piezoelectric composite with modified polymer phase is designed and evaluated in this work. In order to reduce the influence of polymer phase on the vibration of piezoceramic pillars, the polymer phase is modified into a sandwich structure, in which epoxy resin is the middle layer and silicone rubber forms the upper and lower layers. Parameters such as resonance frequency, sound velocity, electromechanical coupling coefficient and characteristic impedance have been simulated by using finite element analysis software. Effects of these parameters are also simulated with different volume fractions of silicone rubber. Piezoelectric composites are fabricated and measured. Experimental results agree well with simulations. Measured electromechanical coupling coefficient shows an improvement of more than 11% over epoxy/ceramic 1-3 piezoelectric composites.