The Automated Fiber placement (AFP) process shows great potential for efficient manufacturing of large
composite structures. However, uncertainties exist on mechanical performance of final product that are
associated with the process induced defects. This experimental work investigates the effect of four principal
defect types, namely gap, overlap, half gap/overlap and twisted tow on the ultimate strengths. Tests
are executed at the lamina level (fiber tension, fiber compression and in-plane shear), as well as at the
laminate level (open hole tension and open hole compression). Then each test is compared with a baseline
configuration exempt from defects. Tests have revealed the minimal effects of a single and isolated
defects on mechanical performance especially at the lamina level (around 5%) compared to the laminate
level (up to 13%).