Fatigue behaviour of unidirectional single-walled carbon nanotube reinforced epoxy composite under tensile load

Abstract

Tension-tension fatigue behaviour of unidirectional, aligned single-walled carbon nanotube (SWNT) rope reinforced epoxy composites were studied. While the slope of the stress-life (S-N) curve of the SWNTs in SWNT/epoxy composites obtained is flat, similar to those of carbon fibre reinforced epoxy composites, the fatigue strength of the former is at least twice that of the latter. Morphology of the fatigue fracture surface of SWNT reinforced epoxy involves matrix plastic deformation and SWNT-bridged matrix cracks. Evidence of good adhesion between SWNTs and epoxy was seen, and pullout length of SWNTs from the matrix is about 30 μm. Results suggest that carbon nanotubes can be used for fatigue resistant, high fracture toughness composites.