Insertion of large diameter through-thickness metallic pins in composites

Existing Through-Thickness Reinforcement (TTR) methods for laminated composites using semi or fully rigid reinforcing elements, like tufting, stitching, and z-pinning, present limitations on element geometry, strength, stiffness. Where these application envelopes are exceeded, TTR insertion results in unacceptable levels of damage to both the composite and/or elements. Here, we demonstrate that low-speed reinforcements into heated prepreg preforms is a feasible robust reinforcement process capable providing accurate placement with minimal tow disturbance compared existing similar pin sizes. The characterised respect forces, mesoscale laminate deformation/damage carbon-benzoxazine preforms. research investigates influence leading edge range diameters (1.2, 1.5, 2.0 mm) preform consolidation states, describing low forces good quality Insertion increase diameter, typically resulting from increased pin-tow contact area friction. Large diameter sizes expand forms materials can be inserted show this method potentially transferred benefit work hole creation, joining, repair.