Effects Of Transducers On Guided Wave Based Structural Health Monitoring

Lead Zirconate Titanate (PZT) transducers are commonly used to generate guided acoustic waves for health monitoring of structures made of isotropic and anisotropic materials. Therefore, characterization of PZT transducers is very important not only for reliability but also for the accuracy of data. In this research, Scanning Acoustic Microscopy (in reflection mode) at 30 MHz excitation frequency is conducted for determining the quality of disc type guided wave transducers. Multiple samples are scanned but only four transducers are selected for further investigation. Guided waves are dispersive in nature and multiple guided wave modes can coexist at single frequency. It has been already reported in the literature that good bonding condition between transducer and testing material is very important to restrict other factors that can affect the strength of recorded signals. Chirp signal is excited in the specimen in a single sided excitation/detection setup to investigate the effects of transducer quality on monitoring plate like structures. Sideband peak count technique is used for comparative study of transducers.