Novel tape termination method for automated fibre placement: Cutting characteristics and delamination suppression

A novel tape termination method for tapering the ply end and removing the fibre discontinuity owing to a dropped ply in a tapered composite was demonstrated. The forces required for this process - referred to as tape scarfing - were experimentally investigated with respect to blade speed, scarfing ratio, tape thickness and width. Tensile tests were conducted on unidirectional laminate specimens with a scarfed ply at two different aspect ratios to examine the effect of scarfing ratio on the delamination behaviour of the specimens. The results showed that the ply scarfing ratio is a critical parameter controlling the cutting force and delamination behaviour in a tapered specimen, and upon reaching a certain threshold delamination can be completely suppressed. The method demonstrated has potential for implementation in commercial AFP machines, theoretically realising a more compact cutting mechanism, with the capability of preventing delamination in the ply drop regions.