In-plane shear damages consideration of hoop wound composite cylinders using acoustic emission method

The objective of this study was to examine the in-plane shear properties of filament-wound composite cylinders and assess the associated damage mechanisms using acoustic emission techniques. Two distinct composite materials, namely carbon/epoxy and glass epoxy, were manufactured for this purpose. The cylinders were subjected to torsion load conditions in accordance with ASTM D5448. Throughout the testing process, various parameters such as torque, angle of torsion, and strain were meticulously recorded. Additionally, the acoustic emission sensors were utilized to capture signals indicating the occurrence of damages. The findings of the study indicate that the in-plane shear strength and shear modulus of the carbon/epoxy specimens surpass those of the glass/epoxy counterparts. The results from acoustic emission testing indicated that in the CFRP specimens, there were no instances of fiber/matrix debonding. Instead, the main mode of damage observed was fiber breakage, accounting for approximately 71% of the total damage detected. On the other hand, in the GFRP specimens, the primary damage mechanism was found to be fiber/matrix debonding, making up approximately 50% of the overall damage recorded.