Effects of defect geometry on fatigue crack growth behavior of cross-ply Ti–6Al–4V/SCS-6 metal matrix composites Original Research Article

The present study describes the fatigue crack growth behavior of [0/90]2s and [90/0]2s laminates of Ti–6Al–4V/SCS-6 composite containing either part-through thickness or through thickness defects under a constant load range at room temperature in air. This study also compares the effect of composite architecture on the fatigue crack growth resistance of these laminates. Acoustic emission was used to detect the number and the location of in situ fiber failures. It was found that the specimens containing part-through thickness defects showed lower crack arrest/catastrophic failure (CA/CF) transitions compared to the specimens where cracks were grown from through thickness defects. Additionally, the higher CA/CF transition of [90/0]2s laminate compared to [0/90]2s laminate irrespective of defect geometry could be attributed to the composite architecture or lay up sequences in these laminates.