Damage Detection in Polymer Composite Laminates Using Different Methods of Clustering by Acoustic Emission

Abstract: One of the prevailed mode of failure in composite material is delamination, since it can cause reduction of stiffness and can propagate throughout other layers. Two major stages of delamination are initiation and propagation. The crucial issue in this zone is to get knowledge about the behavior of such materials. Different methods such as numerical methods, acoustic emission (AE), modeling, etc., are applied and one of the appropriate methods in damage categorization of composite materials is AE. In this article, three procedures are applied for damage clustering using AE technique. The base of this method is stress waves released from the damage source. Test set-up involved end notch flexure (ENF) test is applied to investigate mode II of delamination. Kohonen self-organizing map (KSOM), k-means and fuzzy c-means (FCM) are used to analyze the AE data. Experimental results and scanning electron microscope (SEM) images reveals three kinds of composite damage. Finally, it shows that AE is an effective tool for structural health monitoring of composite materials that permit timely intervention to avoid component failure.