This study focuses on understanding the stiffness and damping characteristics of carbon nanocoil (CNC)/polymer composites. To determine the effective elastic and viscoelastic properties of a polymer reinforced with aligned CNCs, the finite element analysis was performed using a three-dimensional unit cell model. The coil morphology of CNCs was examined using a scanning electron microscope. The effects of coil diameter, tube diameter, coil pitch and number of coil turns on the effective properties are discussed. The effective properties of a polymer reinforced with randomly oriented CNCs were also predicted by the results for the unit cell model. The tradeoffs between stiffness and damping characteristics are assessed by changing the volume fraction and geometrical parameters of CNCs. Additionally, experimental measurements of the elastic modulus and the loss factor of the manufactured CNC/polymer composites were carried out by using dynamic mechanical analysis. The predictions were then compared with the experimental results. Furthermore, scanning electron microscopy was performed to observe the fracture surface of CNC/polymer composites.
2008 by The Japan Society of Mechanical Engineers