Elastic and mechanical properties of carbon nanotubes

We present a comparative study of energetic, structural and elastic propert ies of carbon and composite singlewall nanotubes using a non-orthogonal tig ht binding formalism. We investigate Young Modulus and Poisson ratio of (n, 0) and (n,n) nanotubes, with n=(5..20). Our calculations predict that carbo n nanotubes have a higher Young Modulus (1TPa) than any of the studied comp osite nanotubes and of the same order that found for graphene sheets withou t defect. We obtain good agreements with the available experimental results .