A numerical analysis of carbon nanotube-based damping in rotating composite structures

Composite structures often exhibit vibrations due to their high specific stiffness, and suppressing these vibrations is critical to increasing the efficiency and performance of the overall system. Previous studies have shown that matrix-embedded carbon nanotubes (CNTs) have the potential to provide a significant increase in the damping characteristics of the final composite, augmenting the materials ability to passively reduce vibrations within the structure. This work investigates the effect of matrix-embedded CNTs on the dynamic response of rotating composite structures using numerical simulations. Empirical damping functions obtained from experimental results describing the loss factor of fiber-reinforced composites with matrix-embedded CNTs are applied to describe the material damping as a function of CNT weight percentage loading and material strain. The numerical simulations explore three different rotating composite structures of increasing complexity: a simple rectangular beam, a helicopter rotor, and a wind turbine blade. The finite element method is applied to solve these transient simulation cases, and the effects of CNT damping, angular speed, and geometric variation on the dynamic response of the different composite structures are explored.