Researchers are claiming that the feasibility of space elevator cable is now realistic, thanks to carbon nanotube technology, proposing its realization within a decade. However, the current view of basing the design of the megacable on the theoretical strength of a single carbon nanotube is naive, as has recently been emphasized. In this paper the role of thermodynamically unavoidable atomistic defects with different size and shape is quantified on brittle fracture, fatigue and elasticity, for nanotubes and nanotube bundles. Non-asymptotic regimes, elastic plasticity, rough cracks, finite domains and size effects are also discussed. The results are compared with atomistic simulations and nanotensile tests of carbon nanotubes. Key simple formulas for the design of a flaw-tolerant space elevator megacable are reported, suggesting that it would need a taper ratio (for uniform stress) of about two orders of magnitude larger than currently proposed.
The role of defects in the design of space elevator cable: From nanotube to megatube
Bedeutung von Defekten für die Auslegung von Kabeln für einen Raumaufzug: vom Nanoröhrchen zum Megarohr
Acta Materialia ; 55 , 15 ; 5269-5279
2007
11 Seiten, 1 Bild, 4 Tabellen, 42 Quellen
Article (Journal)
English