Interlaminar Reinforcement of Composite Rotorcraft Components via Tailored Nanomorphologies of Aligned Carbon Nanotubes (A-CNTs)

Composites are often used in aerospace applications due to their superior specific strength and stiffness properties, as well as their resistance to fatigue and corrosion. In particular for rotorcraft, composites offer additional benefits for their versatility in tailoring material properties for such components as rotor blades. However, rotors introduce additional challenges by including multiple composite materials in the laminate with dissimilar thermal expansion coefficients and stiffness, as well as ply drop-offs. Both of these features can lead to interlaminar failure, as they provide a “weak point” at ply interfaces. This SBIR aims to develop a means for interlaminar reinforcement via interface tailoring with aligned carbon nanotubes (A-CNTs). MDC will be partnering with MIT, who has previously demonstrated compelling evidence that properly designed A-CNTs can improve interlaminar (and intralaminar) performance in composite laminates. Now, in the proposed effort, we will extend these improvements to the special cases of ply drop-offs and dissimilar ply fibers relevant to rotor blade applications, utilizing recently developed nano-morphology tailoring of the A-CNTs towards ~10X increase in CNT volume fraction and alternative CNT alignment. During the Phase I effort, prototype components will be manufactured and tested with and without CNT reinforcement to validate the performance benefits.