Use of Piezoelectric Films for NDT Applications

摘要

Poly(vinylidene fluoride) i.e. (PVDF) films and its copolymer with trifluoroethylene P(VDF-TrFE) have found many applications for electromechanical devices which perform energy conversion between the electric and mechanical forms. They have been used in several fields like alarms or stress gauges but have never been commonly used for Non Destructive Testing. EADS CRC has undertaken some evaluation tests using PVDF and copolymer for NDT applications. The results obtained are very promising for acoustic emission, ultrasonic inspection within assembled parts or in-service impact detection for instance. The advantages of those piezoelectric films compared to "traditional" piezoelectric transducers are numerous: flexible, light, easy to handle, designed at fashion, cost-effective... These properties should lead to new NDT applications which were unconceivable so far. This presentation will give an overview on recent tests and optimisations of PVDF transducers. The results will shed some light on the strong potential applications into the aeronautic field.