Investigation of fracture toughness parameters of epoxy nanocomposites for different crack angles

Abstract

Abstract The effects of single-walled carbon nanotubes (SWCNTs) on the mechanical properties of nanocomposites with epoxy matrix were studied, with the emphasis on fracture toughness under tensile loading conditions. It has been demonstrated that adding CNTs into polymer-based materials can improve the mechanical properties of this material. CNTs possess a certain potential to improve the fracture toughness of epoxy systems due to their mechanical properties and increase the fracture toughness of nanocomposites. Since the fracture toughness parameters were best manifested in the scaling properties and were the main parameters, the angles of different cracks have been simulated in a 3D finite element framework and the effects of different angles of crack, on the fracture toughness of polymers, have been modeled and investigated. The simulations are run for different bias angles. The influence of angle, the crack lengths and the variations of different lengths of nanocomposite in different volume fractions (vol%) are investigated. That is to say, at first, nanocomposites had a significantly higher fracture toughness compared to the pure epoxy. We found that nanocomposites, in the presence of SWCNTs, had a greater effect on fracture toughness of nanocomposites in a greater volume of fractions. Also, the nanocomposites exhibited a significant increase in fracture toughness, with zero angle of crack compared with greater angles. In addition, it is found that at a constant volume fracture, fracture toughness, increases by increasing crack lengths.