Ultimate strength of carbon nanotubes: A theoretical study

The ultimate strength of carbon nanotubes is investigated by large-scale quantum calculations. While the formation energy of strain-induced topological defects determines the thermodynamic limits of the elastic response and of mechanical resistance to applied tension, it is found that the activation barriers for the formation of such defects are much larger than estimated previously. The theoretical results indicate a substantially greater resilience and strength, and show that the ultimate strength limit of carbon nanotubes has yet to be reached experimentally. Nanotubes are indeed the strongest material known.