Assessment of Steering Capability of Automated Dry Fibre Placement Through a Quantitative Methodology

In the aerospace industry, major composite structural components are manufactured by Automated Fibre Placement (AFP), which is an automated material deposition process laying up slit prepreg tapes on a mould. Dry fibre material has emerged as a promising alternative to prepreg for AFP with, among others, the claimed benefit of better conformability to steered paths. However, any radius of steering will inevitably introduce disturbance in the fibre alignment which is expected to increase with the degree of tape curvature. The minimum steering radius is frequently used to describe the smallest radius that can be achieved during lay-up. However, this is often a machineand material-dependent parameter difficult to estimate objectively and therefore hardly reliable. An operator-independent metric to quantify the quality of a steered path would provide guidance for design. In order to address this challenge, this work presents a quantitative analysis t of outof- plane fibre waviness of the preform. The measurement is based on a 3D surface roughness measurement, and quantifies the out-of-plane wrinkling generated on the deposited surface. The feasibility of the method is demonstrated and shown to be a useful quantitative criterion to quantify material dependent wrinkle formation.