73 - Use of AE for characterization of damage mechanisms in composite accumulator

This study presents the results of a collective study performed at CETIM for industrials of the hydraulic transmissions profession. The purpose is to develop an accumulator made of composite material, carbon fiber and thermosetting resin, and to characterize the behavior of this accumulator by both static and cyclic pressure tests. Knowledge of the damage mechanisms evolution occurring during these tests is studied by Acoustic Emission monitoring combined by strain gage measurements. The AE monitoring results are compared to the failure criteria used in the design model in order to correlate the different damage mechanisms occurring in each layer with the detected AE signals. Further mechanical tests were carried out on samples taken from accumulators tested at different pressure levels. Visual observations by video camera combined with AE data recording during these tests validated the identification and the progression of the different damage mechanisms in different layers.