Transverse Cracking Induced Acoustic Emission in Carbon Fiber-Epoxy Matrix Composite Laminates

Transverse cracking induced acoustic emission in carbon fiber/epoxy matrix composite laminates is studied both experimentally and numerically. The influence of the type of sensor, specimen thickness and ply stacking sequence is investigated. The frequency content corresponding to the same damage mechanism differs significantly depending on the sensor and the stacking sequence. However, the frequency centroid does not wholly depend on the ply thickness except for the inner ply crack and a sensor located close enough to the crack. Outer ply cracking exhibits signals with a low-frequency content, not depending much on the ply thickness, contrary to inner ply cracking, for which the frequency content is higher and more dependent on the ply thickness. Frequency peaks and frequency centroids obtained experimentally are well captured by numerical simulations of the transverse cracking induced acoustic emission for different ply thicknesses.

Automated summary

This study investigates the acoustic emission induced by transverse cracking in carbon fiber/epoxy matrix composite laminates through experimental and numerical analysis. The influence of sensor type, specimen thickness, and ply stacking sequence is examined. The study reveals that the frequency content corresponding to the same damage mechanism varies significantly depending on the sensor and stacking sequence. However, the frequency centroid is not solely dependent on the ply thickness except for inner ply cracking. Outer ply cracking exhibits low-frequency signals that are not greatly influenced by the ply thickness, while inner ply cracking shows higher frequency content that is more dependent on the ply thickness. Experimental frequency peaks and centroids are well captured by numerical simulations for different ply thicknesses.