Multi-Scale Analysis for Tensile Mechanical Properties of Carbon Nanotube Fibers by In Situ Raman Spectroscopy

This paper presents an experimental study on the tensile mechanical properties of carbon nanotube (CNT) fibers by in situ Raman spectroscopy. The comprehensive spectral information, such as Raman shift, width and intensity, are recorded during the whole loading–unloading–reloading procedures of CNT fibers. Based on the experimental results, the elastic-plastic deformation evolution of CNT fibers are analyzed at multi-scale levels. It is found that the elastic deformation of the fiber is mainly attributable to the elastic stretching of the CNTs inside the bundles. And the plastic deformation is caused mainly by the slippages at the interfaces among CNTs inside the bundles. Meanwhile, the CNTs deform elastically during the whole loading–unloading–reloading procedures.