A new method for the determinaton of elastic properties of thin piezoelectric PZT fibers

For the optimization of thin piezoelectric fibers it is necessary to determine their dielectric, elastic and piezoelectric properties. We developed analytical approximations to calculate the elastic coefficient S-33,f(E) of the fibers from the effective coefficients C-33,eff(E) and S-33,eff(E) of 1-3 composites containing such fibers. The analytic solutions have been checked by modeling with the Finite-Element-Method and compared with experimental results of model structures containing rods of soft PZT ceramic with known material properties. The elastic coefficients of the 1-3 composites were determined using the resonance method with different sample geometries for different vibration modes. The new method was applied to characterize the elastic properties of undoped PZT fibers with a Zr-content from 48 to 58 mol%. The elastic coefficient S-33(E) of the fibers shows a maximum value of 15*10(-12) m(2)/N at a Zr/Ti ratio of 51/49.