A modally-selective, variable-length anisotropic piezocomposite transducer is designed for guided wave (GW) structural health monitoring applications. The transducer dimensions needed to maximize individual modes are selected based on 3-D elasticity models for GW excitation by finite dimensional transducers. This theory is used to determine these transducer dimensions as a function of the wave phase velocity, and normalized by the substrate thickness. The design and fabrication of the transducer are subsequently described, and a set of experimental tests is conducted in pristine isotropic structures to characterize the actuation and sensing performance of the device. It is shown that the transducer dimensions can be tailored to obtain specific symmetric to antisymmetric mode transmission ratios.
Characterization of sensor performance and durability for structural health monitoring systems
