Cluster Analysis of Acoustic Emission Signals for Carbon/Epoxy Composite in Four-point Bending Test (RESEARCH NOTE)

Due to the extensive use of composites in various industries and the fact that defects reduce ultimate strength and efficiency during operation, detection of failures in composite parts is very important. The aim of this paper is to use Acoustic Emission (AE) non-destructive method in four-point bending test of carbon/epoxy composite to analyze and examine the failure mechanisms. This method is based on waves that activated from defects in structures which are built during loading. Sensors collected acoustic signals which created by the separated layers. Each stage of failure is in specific frequency range and explains a specific mechanism. Clustering of these signals is done with C-mean and K-mean algorithm and compared with the results of previous works. The failure process was shown to proceed through the four stages. In both algorithms, each cluster has coincidence with one part of these stages.