Piezoelectric and Electrostatic Polymeric Transducers for Acoustic Emission Detection

摘要

The work performed during the contractural period falls into three distinct parts: (1) the fabrication of ultrasonic transducers for acoustic emission detection using polyvinylidene fluoride (PVDF) active elements. (2) the fabrication of electrostatic transducers using thin films of non-polar polymers such as polypropylene and polytetrafluoroethylene. (3) the development of a flexible composite material with piezoelectric properties using powdered ceramic (PZT) dispersed in a polymer matrix. The first period report dealt with the design and characterization of PVDF transducers. The second report compared the sensitivity of PVDF transducers with polypropylene electrostatic transducer designs. Further work performed to determine optimum charging conditions for high sensitivity and repeatability of electrostatic responses was described in the third report. This report briefly describes the work performed over the entire project and then describes, in detail, the development and piezoelectric characterization of a flexible composite material which may be used for acoustic emission monitoring applications.