Experimental investigation of the effect of defects in Automated Fibre Placement produced composite laminates

Automated composite manufacturing processes such as Automated Tape Laying (ATL) and Automated Fibre Placement (AFP) are effective methods to produce high quality, lightweight parts. Typically, preimpregnated fibres or tapes are laid side-by-side onto a tooling surface to generate the composite preform. Although these two main technologies are widely used to produce large composite components, inconsistencies such as overlapping tapes or gaps between adjacent tapes may occur during the manufacturing. Within this study, the effect of gaps and overlaps, so-called defects, has been investigated experimentally. Tensile and compressive testing has been carried out on specimens with a quasi-isotropic, symmetric layup into which artificial defects in various defined formations were introduced. Of particular interest were the strength knockdown factors and changes in the failure mode.