Analysis of acoustic emission from composite laminate testing

Composite laminate are not a simply material but a complex structure. Fibre and matrix combined together generate the composite lamina, the overlapping of more than one lamina generate the composite laminate. Consequence of this architecture is a complex behaviour during the service of component realized by such material. In particular the identification of the performances and the strength limits of this kind of material are not so simply to be identified. The failure mode that affect the composite laminate performances are more than one and they are generally superimposed. The technique used to characterized the composite laminate performances are similar to the ones used for the homogeneous material: tensile and/or compression or bending static tests and/or fatigue and/or fracture tests. However, because of composite laminate material complexity, the description of its performances requires the usage of techniques to investigate failure modes sequence and superimposition. In this work the approach used to investigate the composite laminate performances in terms of failure modes is the Acoustic Emission (AE) monitoring. Five kind of composite laminate have been considered and for each of them the AE information recorded during the laboratory test have been analysed in order to identify the progress of failures inside the material.