DYNAMIC SURFACE DISPLACEMENT MEASUREMENT IN 1-3-PIEZOCOMPOSITE AND 1-1-3-PIEZOCOMPOSITE

The sensitivity of 1-3 piezocomposites can be improved by the addition of a third phase or interlayer around the piezoceramic rods which res ults in a composite with 1-1-3 connectivity. In the current investigat ion, dynamic surface displacements of both 1-3 and 1-1-3 piezocomposit es were measured using a laser Doppler heterodyne interferometer. Dyna mic displacement profiles showing the nonuniform deformation of the pi ezoelectric rod and the nonpiezoelectric polymer were obtained at 10 H z, 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 considere d. The experimental measurements demonstrated that both the surface di splacement profile and the maximum rod displacement varied with freque ncy and interlayer properties. The dynamic displacement profiles were also compared with previously measured static displacement profiles. ( C) 1998 American Institute of Physics. [S0021-8979(98)06722-X]