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The laminated composites have many advantages such as high specific strength and specific stiffness. Despite of these advantages, they are prone to different damage mechanisms. This paper focuses on quantification of damage mechanisms in standard Open-Hole Tensile (OHT) laminated composites using Acoustic Emission (AE) and Finite Element Method (FEM). These damages include three main mechanisms, matrix cracking, fiber/ matrix debonding and fiber breakage. To this aim, OHT tests were carried out. The specimens fabricated from two types of glass/epoxy composite materials with [0]5S lay-up and [90]5S lay-up. AE accompanied with wavelet-based approach was then used to detect and quantify damage mechanisms of the specimens. FE analysis based on Hashin criteria was then utilized to simulate the damage mechanisms in the specimens and to validate the AE-wavelet based results. The comparison of applied methods show that the results of the AE-wavelet based approach are in very good agreement with the FEM results. Finally, it was concluded that the AE method has a good applicability to determine the damage mechanisms in laminated composite structures and to predict the remaining life-time of the structure.

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Delamination is one of the major failure modes of the laminated composite material, which is responsible for the stiffness degradation of these materials. Hence, it is necessary to investigate this damage mechanism in these types of materials in order to distinguish their behaviors and their effects on the residual strength of the composite laminates. In this paper, a very capable procedure is proposed to assess delamination using Acoustic Emission (AE) method in composite laminates. Firstly, a novel procedure was established to decompose the fundamental Lamb wave modes in small size specimens. The damage mechanisms in End Notched Flexure (ENF) in woven and unidirectional specimens were then distinguished using Fuzzy Clustering Method (FCM). Subsequently, the crack-arrest phenomenon was inspected in each specimen. Next, experimental and Cohesive Zone Modeling (CZM) methods were done to characterize the delamination using ENF specimens. The results displayed how, it is possible to effectively reduce the effect of propagating media such as attenuation of AE signals using the new proposed procedure. In conclusion, the results of this research could lead to proficiently distinguishing different damages in laminated composite using AE Lamb-based technique.