Acousto-ultrasonic analysis of defects in composite specimens used in transportation domain

Metal parts have recently been substituted with composite in the transport industry due to their characteristics, which include increased strength, stiffness and reduced weight. Acousto-ultrasonics is an inspection technique, which combines the acoustic emission methodology with ultrasonic simulation of stress waves to assess defect states in materials. Acousto-ultrasonics belong to the family of inspection tools, which emerge to identify and measure occurred damage or decay state of transportation modes and infrastructure. In this paper, we attempt to detect defects by performing initial experiments with composite specimens. Specifically, the attenuation of simulated acoustic emission events are measured aiming to further investigate the phenomenon of edge reflections from small composite specimens. Also, only two features from the signal can be used to detect two different types of faults. Finally, a new triangular–like larger specimen is introduced and assessed using the two sensors, in order to show the difference of the two aforementioned features when two different material and dimension specimens are used