A multi-scale analysis of the structural stability of a carbon nanotube-polymer composite material is developed. The influence of intrinsic molecular structure, such as nanotube length, volume fraction, orientation and chemical functionalization, is investigated by assessing the relative change in critical, in-plane buckling loads. The analysis method relies on elastic properties predicted using the hierarchical, constitutive equations developed from the equivalent-continuum modeling technique applied to the buckling analysis of an orthotropic plate. The results indicate that for the specific composite materials considered in this study, a composite with randomly orientated carbon nanotubes consistently provides the highest values of critical buckling load and that for low volume fraction composites, the nonfunctionalized nanotube material provides an increase in critical buckling stability with respect to the functionalized system.
I. IntroductionDevelopment of high-stiffness and high-strength materials is an important part of the quest to advance aerospace vehicle structures. As a relatively new class of materials, single-walled carbon nanotube (SWNT) -reinforced polymer composites provide many opportunities to demonstrate the performance potential of nanostructured materials for use in structural applications. In particular, SWNT materials have demonstrated the potential for order-of-magnitude increases in strength and stiffness relative to standard carbon-fibers used in typical polymeric composites.