Damage arrest mechanisms in nanoparticle interleaved composite interfaces

Abstract

The effectiveness of carbonaceous nanoparticles in arresting and delaying damage in nanocomposites has been attributed to multiscale toughening mechanisms. To explore their application in joined interfaces of composites, this study investigates the use of carbon nanotube (CNT) interleaved films for co-cured joining of composite parts and their consequent effects on the interfacial fracture toughness. Carbon nanotubes dispersed in a thermoset resin into thin films of two discrete thicknesses (200 μ and 500 μ) and three concentrations of CNT dispersion were chosen for this study (0.5% wt., 1% wt., and 2% wt.). The films were semi-cured in the oven before being incorporated as interleaves in the composite laminate interface. Fracture toughness of the interface in mode I loading conditions was determined through double cantilever beam (DCB). Micrographs of the fracture surfaces reveal a slip-and-stick based crack jump and arrest phenomena in mode I when nanoparticles are added to the interleaved interface. The thickness of the interleaves has a more significant effect on mode I toughening mechanisms than the concentration of the nanoparticles.