Investigation of an improved time of arrival detection method for acoustic Emission signals and its applications to damage characterisation in composite materials

An improved Time of Arrival (ToA) estimation method is presented for picking the arrival of the Acoustic Emission (AE) signals. The performance of this method is compared with the recently developed ToA estimation methods based on time-varying correlation built on surrogate function, and the non-stationary time series based Akaike Information Criterion (AIC). The method proposed in this research work outperforms the other two methods in terms of error percentage, while having the same computational time as the latter. The performance analysis shows that the developed method is most suitable for AE signals generated from composite structures. Furthermore, the application of this method is explored by characterising the damage evolution in cenosphere particle reinforced unsaturated polyester syntactic foam composites. The results show that the AE descriptors calculated from the ToA are able to distinguish the evolution of tensile and shear cracks in the brittle composite.