Mechanics of carbon nanotube networks: microstructural evolution and optimal design

Carbon nanotube networks feature outstanding mechanical performance, and also hierarchical structures and network topologies. In this paper we investigate their structure-property relationship through mesoscale molecular dynamics simulations. We find that their microstructures undergo remarkable evolution under mechanical loads. The correlation between applied strain, microstructural evolution and failure mechanism, especially the bundling process and evolution of bridging carbon nanotubes, is discussed based on the simulation results. Based on the insights of the underlying mechanisms, further engineering approaches on the carbon nanotube networks towards enhanced mechanical properties are proposed and validated, e.g., by including intertube cross-links that resist shear, maintain the network topology and improve strain affinity.