Universal Strength Scaling in Carbon Nanotube Bundles with Frictional Load Transfer.

Carbon nanotubes (CNTs) individually display exceptional mechanical properties, but the strength of their mesoscale assemblies such as bundles has a fundamental disconnect, with limited understanding of its scaling. Here we use coarse-grained implementation of a CNT interface with prescribed length distributions and parametrized cross-link density, providing two essential control parameters. It is shown that a linear relationship between strength of the bundles and these control parameters exists, across multiple hierarchies of nanotube interfaces. Furthermore, all geometrical perturbations caused by length distribution and bundle dimensions result in a net stress concentration effect, without influencing the scaling behavior.