Resonant characteristics of piezoelectric composites: analysis of spurious modes in single and multi-element ultrasonic transducers

This paper examines in detail the generation of high frequency inter-pillar (lateral) resonances in 1-3 piezoelectric composites, through experiment and finite element analysis (FEA) with the PZFlex package, both in monolithically electroded composites and in multi-element arrays based on a 1-3 piezoelectric composite substrate. While thickness modes are accurately described by standing wave formation within the transducer, other interpillar modes will be clearly shown to be generated due to Lamb waves propagating through the substrate, between pillars and between elements in the single and multi-element cases respectively.