Lead zirconate titanate (PZT)/epoxy 1-3 piezocomposite rings were fabricated with PZT volume fractions φ ranging from 0.82 to 0.94 and with a small epoxy width of 77 μm in order to investigate their resonance characteristics and to reveal the mode coupling. Four major resonance modes were observed, namely the coupled longitudinal-thickness fHand lateral fL1and fL2mode resonances of individual PZT elements inside the rings as well as the radial fRand wall-thickness fWmode resonances of the whole rings. No stopband resonances were observed in the frequency range of 1 to 10 MHz. fHwas found to increase linearly with the decrease in element height while fL1and fL2remained constant. When the height and width of the elements became comparable, coupling of fHwith fL1and fL2occurred. The observed fH, fL1, and fL2for all samples agreed with those calculated by the mode-coupling theory. fRand fWwere almost independent of the ring thickness but increased as φ increased. A guide of operating fHin the rings without causing mode coupling was presented to optimize the composite structure for transducer design.
ASJC Scopus subject areas
- Physics and Astronomy(all)