Characterization of Splitting Growth Behavior in Unidirectional Carbon Fiber Reinforced Plastic Laminates with a Notch Subjected to Fatigue Load

: Tensile fatigue tests using acoustic emission (AE)measurements were performed on unidirectional carbon fiber reinforced plastic (CFRP)laminates with a notch to investigate the relationship between the fatigue damage behavior and the associated AE behavior. Immediately subsequent to theinitiation ofthetests,splitting occurred along thedirection ofthefiberfrom the tip of a notch, and rapidly progressed for all investigated stress levels. Thereafter, the rate of development was almost constant after 3×104 cycles and the AE behavior also changed. These results indicate that the AE behavior is indicative ofthe splitting behavior.We discussed the AE behaviorbased on theexperimentalresultsforthesplitting behaviorand therelationship between theAE,and thefatiguedamagebehavioroftheunidirectionalCFRP laminatewasobtained.From this relationship,it is possible to predict the damage type,size,and quantitybycomprehensively evaluating thefrequencycharacteristics,and each parameter oftheAE waves.