Berlin 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
DF: Fachverband Dielektrische Festkörper
DF 5: Electrical, mechanical and electromechanical properties
DF 5.2: Vortrag
Montag, 26. März 2012, 16:25–16:45, EB 107
Piezoelectric properties of single ceramic fibres: Comparison of two methods — •Sabine Kern, Christoph Pientschke, and Ulrich Straube — Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle
Composites containing piezoelectric fibres embedded in a polymer matrix are used for sensoric, actuatoric and ultrasonic applications. Accurate knowledge of the piezoelectric properties of the fibres is desirable to optimise these materials. In this work, the determination of the small-signal piezoelectric coefficient d33 of ceramic PZT-fibres was realised with two methods by using a capacitive displacement sensor. On the one hand, the effective d33 of 1-3 fibre composites is measured. Then the d33 of the fibres can be calculated using the ceramic’s and polymer’s elastic properties and the fibre volume content. Independently, the d33 of the fibres was determined directly by measuring the longitudinal piezoelectric strain. PZT-fibres with 250 µm in diameter and 1-3 composites with a fibre volume content ν of 35% and 65% that contain these fibres were studied. The measurements at single fibres show well-reproducible values with a small standard deviation for the d33, whereas the local measurements at composites show a larger range of variation in their effective d33, especially for composites with lower ν. This higher variance is mainly influenced by the locally highly varying fibre volume content and less by the fibre properties themselves. Moreover, composites with larger ν show higher d33 than composites with lower ν. Finally, the d33 of single fibres derived from the composites’ properties was compared with the directly measured values.