Thermoset automated fibre placement

Thermoset automated fibre placement is a promising processing technology for the automated manufacture of carbon fibre-reinforced polymer parts. During the process, so-called slit-tapes of non-cured, thermoset carbon fibre-reinforced polymers are laid-up onto single or double-curved surfaces by a placement head applying heat and compaction. The tow shape allows to position the carbon fibre in loadpath direction along lay-up trajectories with a non-geodesic curvature. This process capability is so-called steering. In-plane fibre waviness and out-of-plane tape buckling are two lay-up effects as a result of steering. These local effects globally influence the mechanical performance of a laminate due to fibre angle deviation. A limit for steering slit-tapes is defined by comparing the inverse of its non-geodesic curvature, so-called steering radius, to a critical value. For a slit-tape of 1/8′′ width, this is assumed to be ∼ 635 mm not taking the respective influence of material properties, process parameters and lay-up geometry into account. Within this thesis, a novel computational method was developed by focusing on the lay-up effect of in-plane fibre waviness for the prediction of steering limits during thermoset automated fibre placement.