Fatigue crack growth of glass fiber reinforced aluminum alloy laminate (Al/GFRP) according to the micro hole location

The diverse studies on Al/GFRP laminates with the circular holes, therefore, have been carried out recently. The recent studies just focused on the behavior of the fatigue crack propagation and the delamination when the shape and the size of the notches were changed. Therefore, this study evaluated the location effect of the defects in the vicinity of the circular notch of the high strength monolithic aluminum and Al/GFRP laminates on the initiation life (N-i) of the fatigue cracks, the relationship between the crack length (a) and the fatigue life (N). In addition, the fatigue crack behavior of Al/GFRP laminates was studied when the fatigue loading and the interlaminar delamination took place at the same time during crack propagation. In conclusions, (1) for the monolithic aluminum, 10% of the failure life at theta(2)=30 degrees was more increased than that at theta(3)=60 degrees. (2) The crack length and the fatigue life behavior of Al/GFR-P laminates according to the location of the artificial defect were different from those of the monolithic aluminum. Namely, the fatigue life of theta(1)=0 degrees and theta(2)=30 degrees were remarkably shorter than those of theta(3)=60 degrees and theta(4)=90 degrees.