Acoustic Emission Technique, an Overview as a Characterization Tool in Materials Science

Abstract

In order to predict the mechanical behavior of a composite during its service life, it is important to evaluate its
mechanical response under different types of external stresses by studying the initiation and development of cracks
and the effects induced by damage and degradation. The onset of damage is related to the structural integrity of the
component and its fatigue life. For this, among other reasons, non-destructive techniques such as acoustic emission
(AE) have been widely used nowadays for composite materials characterization. This method has demonstrated
excellent results on detecting and identifying initiations sites, cracking propagation and fracture mechanisms of
polymer matrix composite and ceramic materials. This paper focuses on commenting the importance of the acoustic
emission technique as a unique tool for characterizing mechanical parameters in response to external stresses and
degradation processes by reviewing previous investigations carried out by the author as participant. Acoustic emission
was employed to monitor the micro-failure mechanisms in composites in relation to the stress level in real-time during
the tests carried out. Some results obtained from different analysis are discussed to support the significance of using
AE, technique that will be increasingly employed in the composite materials field due to its several alternatives for
understanding the mechanical behavior; therefore, the objective of this manuscript is to involve the benefits and
advantages of AE in the characterization of materials.