Fatigue delamination of a carbon fabric/epoxy laminate with carbon nanotubes

This paper describes the results related to the crack growth rate measurement on double cantilever beam (DCB) specimens made of a carbon-fibre fabric-reinforced multifunctional epoxy composite. Two plates were evaluated where the resin was enhanced using a combination of 0.5% carbon nanotubes (CNTs) and Glycidyl POSS (GPOSS) flame retardant for one of the plates. Loading in mode I was displacement-controlled with R = 0.1, f = 4 Hz and a constant maximum strain energy release rate (GI)max during the cycle. The value of (GI)max was defined to be from 20% up to 60% of the mode I interlaminar fracture toughness. The specimens enhanced by CNTs and GPOSS highlighted a significant decrease in the fatigue crack growth rate of approximately 80%. The crack growth rate was also observed to be significantly related to the interface of the weft and warp tows of the plain weave.