This study investigates the stiffness retention in cyclic-loaded carbon fibre-reinforced polymer (CFRP) composites produced using a novel automatic tape laying technique called the Fill Multilayer. The research compares the fibre alignment and flexural strength of CFRP composites made via hand laying with those produced by the Fill Multilayer. The Fill Multilayer uses a 16-head tape-laying machine to lay unidirectional (UD) carbon fibre fabrics with deliberate misalignment to examine the effect of fibre orientation and random longitudinal misalignment. The results show that the Fill Multilayer significantly reduces fibre alignment scatter, achieving a 52% reduction compared to hand-laid samples. The alignment of the Fill Multilayer-produced composites is much more consistent, with a fibre misalignment of only 1.68°, leading to a higher modulus and flexural strength. The study also found that shear-based failure increases exponentially as fibre alignment decreases. The Fill Multilayer-produced composites have a higher void concentration due to ultrasonic welding, but also the highest modulus and flexural strength. The study highlights the importance of fibre alignment in determining the mechanical performance of CFRP composites. The results show that the Fill Multilayer produces composites with significantly better mechanical properties compared to hand-laid samples. The study also found that the Fill Multilayer has a higher reproducibility and better control over fibre alignment, leading to improved stiffness retention in cyclic-loaded composites. The study concludes that the Fill Multilayer is a promising technique for producing high-performance CFRP composites with consistent mechanical properties.This study investigates the stiffness retention in cyclic-loaded carbon fibre-reinforced polymer (CFRP) composites produced using a novel automatic tape laying technique called the Fill Multilayer. The research compares the fibre alignment and flexural strength of CFRP composites made via hand laying with those produced by the Fill Multilayer. The Fill Multilayer uses a 16-head tape-laying machine to lay unidirectional (UD) carbon fibre fabrics with deliberate misalignment to examine the effect of fibre orientation and random longitudinal misalignment. The results show that the Fill Multilayer significantly reduces fibre alignment scatter, achieving a 52% reduction compared to hand-laid samples. The alignment of the Fill Multilayer-produced composites is much more consistent, with a fibre misalignment of only 1.68°, leading to a higher modulus and flexural strength. The study also found that shear-based failure increases exponentially as fibre alignment decreases. The Fill Multilayer-produced composites have a higher void concentration due to ultrasonic welding, but also the highest modulus and flexural strength. The study highlights the importance of fibre alignment in determining the mechanical performance of CFRP composites. The results show that the Fill Multilayer produces composites with significantly better mechanical properties compared to hand-laid samples. The study also found that the Fill Multilayer has a higher reproducibility and better control over fibre alignment, leading to improved stiffness retention in cyclic-loaded composites. The study concludes that the Fill Multilayer is a promising technique for producing high-performance CFRP composites with consistent mechanical properties.