Abstract:
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This report presents all the results of the final degree project done during a stage within the service TE374 (Physical, Thermical Atmpsphere Re-entries Test and Analysis) at EADS ASTRIUM Space Transportation Aquitaine, an enterprise of the EADS group, european leader in aerospace industry. This training period had as main objective to achieve the procedure for an Acoustic Emission test in a cryogenic environment, and study and interpretation of Acoustic Emission captures. On one hand, an adhesive (CAF) procedure for cryogenic environment has been validated. To reach the objective different steps have been performed: At first place a repeatable test procedure has been searched. Secondly, a repeatable adhesive procedure for the Acoustic Emission captors has been defined. After, it has been tested in a traction test in a cryogenic environment, and a cause of the non satisfactory result, an alternative has been searched. A cianolyte adhesive has been chosen, compared with CAF and validated in cryogenic environment. An exploitation of the Acoustic Emission captures has also been performed. Different kinds of characteristic hits have been identified by the frequency composition of the wave. On the other hand, a deepening in the Acoustic Emission technique on composite materials has been done. The linear localisation of damage sources in a prototype qualification test has been performed with great results. The data has been also analysed and different families of hits have been identified as well. At last, the influence of two composites nature in the wave propagation has been investigated because it could add an extra attenuation in the AE signals. The results expose that the stacking sequence introduces a different radial propagation diagram, with maximums in fibre directions. |