Book Description

Hierarchical advanced composite structures comprised of both nano- and micro-scale fibers are currently being studied as next-generation materials for multifunctional aerospace applications. Carbon nanotubes (CNTs) are an attractive reinforcing fiber for aerospace composites due to their scale and superior specific stiffness and strength, as well as their potential to enhance multifunctional properties. Nano-scale fibers can address current challenges in composites such as relatively weak through-thickness properties that occur due to matrix-rich regions, including those found at interlaminar ply interfaces, that are prone to delamination and lead to overall reductions in mechanical properties. Existing technologies such as stitching, z-pinning, and braiding provide through-thickness reinforcement; however, these improvements come with simultaneous reductions in in-plane properties. CNTs provide an alternative fiber reinforcement, though currently the literature reveals that laminate mechanical property enhancements are lower than expected. Investigations into how CNTs affect laminate properties have stalled due to difficulties with producing quality laminates and controlling CNT orientation and dispersion. In this work, manufacturing routes of a nano-engineered composite are developed to provide consistent control over laminate quality while placing aligned CNTs (A-CNTs) in the polymer matrix in the interlaminar and intralaminar regions. Manufacturing techniques are developed for growing aligned CNTs on a three-dimensional woven microfiber substrate and infiltrating the fuzzy fiber plies with polymer to realize the Fuzzy Fiber Reinforced Plastics (FFRP) architecture. These FFRP laminates show