In order to explore potential applications for Active Fiber Composite (AFC) elements
made from piezoelectric fibers for structural integrity monitoring, a model experiment for leak
testing on pipe segments has been designed. A pipe segment made of aluminum with a diameter of
60 mm has been operated with gaseous (compressed air) and liquid media (water) for a range of
operating pressures (between about 5 and 8 bar). Artificial leaks of various sizes (diameter) have
been introduced. In the preliminary experiments presented here, commercial Acoustic Emission
(AE) sensors have been used instead of the AFC elements. AE sensors mounted on waveguides in
three different locations have monitored the flow of the media with and without leaks. AE signals
and AE waveforms have been recorded and analysed for media flow with pressures ranging from
about 5 to about 8 bar. The experiments to date show distinct differences in the FFT spectra
depending on whether a leak is present or not.
