Dynamic surface displacement measurement in 1-3 and 1-1-3 piezocomposites

The sensitivity of 1-3 piezocomposites can be improved by the addition of a third phase or interlayer around the piezoceramic rods which results in a composite with 1-1-3 connectivity. In the current investigation, dynamic surface displacements of both 1-3 and 1-1-3 piezocomposites were measured using a laser Doppler heterodyne interferometer. Dynamic displacement profiles showing the nonuniform deformation of the piezoelectric rod and the nonpiezoelectric polymer were obtained at 10 Hz, 100 Hz, and 1.0 kHz. Measurements of the displacement at the center of the piezoelectric rod were performed over the frequency range from 10 Hz to 27 kHz. Three different interlayer conditions were considered. The experimental measurements demonstrated that both the surface displacement profile and the maximum rod displacement varied with frequency and interlayer properties. The dynamic displacement profiles were also compared with previously measured static displacement profiles.