Acoustic Emission Applied to Pipes of GFRP that have been Exposed to Corrosive Mediums

Abstract

The aim of this study was to validate that the acoustic emission technique as a nondestructive test is able to check GFRP which are going to transport corrosive liquids. For this purpose, different tubes made by filament winding, were exposed to different corrosive liquids at 50°C and finally tested at compression and acoustic emission simultaneously. These pipes were also tested by microscopy to verify that the results achieved by Acoustic Emission and by this technique were comparable. Besides, in order to study several variables an experimental design was carried out. All the results were introduced in a statistical program. The purpose was to consider all these factors and assess which ones were the most important in the corrosion process. The main factors considered in the design were: the different corrosive mediums (HCl and NaClO), the postcured of the samples, concentration of the corrosive medium, and the exposure time. The results showed that the A. E. technique allows to determine the state of the pipes which have been exposed to corrosive mediums and even, it allows to distinguish between two different mediums. So, the utility of the technique is proved in this kind of degradation processes.