Effect of CNTs debonding on mode I fracture toughness of polymeric nanocomposites

This article deals with the effect of CNTs debonding from the surrounding matrix on the fracture toughness of carbon nanotubes/epoxy nanocomposites. Hence, a multiscale modeling of fracture toughness improvement of nanocomposites due to CNTs debonding was developed. This energy dissipation mechanism takes place at a zone around the crack tip. A representative volume element containing a carbon nanotube, its surrounding resin and the interphase was chosen in order to develop the multiscale model. Using experimental data available in the literature, the influence of several parameters such as weight fraction of the CNT, the interphase thickness and Young's modulus were studied by the present model. It was concluded that the interphase characteristics as well as the CNT weight fraction strictly affect the fracture toughness enhancement caused by the debonding mechanism and the debonding stress around the CNT. In addition, the influence of CNTs debonding on the fracture toughness of nanocomposites was investigated. (C) 2016 Elsevier Ltd. All rights reserved.