Experimental study on the influence of optimised automated fibre placement processing parameters on the impact response and residual flexural strength of AS4/APC-2 laminates

This study explores automated fibre placement (AFP) for manufacturing impact-resistant carbon fibre/PEEK (AS4/APC-2) laminates by modifying the in-situ consolidation parameters. However, manufacturing these laminates without compromising their mechanical properties is challenging owing to the synergistic effect of parameters. The results indicate that a fast deposition rate and high consolidation force are associated with improved impact resistance and a higher threshold energy for damage. Improvements in flexural strength (27.4 %) and modulus (22.6 %), are achieved in non-impacted specimens. Acoustic emission monitoring was conducted during flexural-after-impact test to correlate the internal damage with the mechanical performance of AS4/APC-2 composites. The experimental results indicated that a fast deposition rate combined with high consolidation force can withstand higher impact loads. The FAI test showed the highest residual flexural strength and stiffness under these parameters, as it effectively resisted low-velocity impact (LVI) damage. However, the slight trade-off observed in post-impact strength suggested the presence of resin-rich areas, which may affect the damage tolerance of the laminates.