Fatigue strength of woven fabric composites with drilled and moulded-in holes

The fatigue strength of glass-fiber woven-roving composites with a circular hole has been examined. Circular holes of two types, drilled and moulded-in, were considered. Experiments on the fatigue life and damage processes in (0, 90)_s and (45, −45)_s woven-roving composites with hole diameters of 5, 10, 14 and 19 mm were conducted. Experimental results show that laminates with moulded-in circular holes exhibit higher fatigue strength than those with drilled holes as a consequence of the altered mode of failure. Photographs of fatigue failure processes and specimen elongation with life are presented. The failure phenomena of laminates with drilled and moulded-in holes are compared and discussed.