Delamination characterization in composite laminates using acoustic emission features, micro visualization and finite element modeling

Acoustic Emission (AE) is a capable approach to characterize delamination initiation and propagation in laminated composite materials. One of the major issues of applying this methodology is to establish a reasonable correlation between delamination initiation and propagation and resultant AE features. To this aim, initiation and propagation of mode I delamination is investigated in glass/epoxy composite materials. Micro and macro observation and acoustical energy were used to develop novel AE-based approaches for investigation of delamination damage. The privilege of these novel approaches is to detect the exact time of initiation of delamination in different laminates which was the lack of previous literature. The Cohesive Zone Modeling (CZM) was used to simulate the delamination growth. Scanning Electron Microscope (SEM) images were also used to investigate damage mechanisms at the interface of crack growth. The results show that AE and CZM approaches present decent capability to characterize delamination. The output of this study could lead to enhancing automatic techniques for structural health monitoring of composite materials.