A combined micromechanical-numerical model to simulate shear behavior of carbon nanofiber/epoxy nanocomposites

In the present research a method was developed that by having the stress-strain behavior of the neat epoxy, the stress strain behavior of carbon nano fibers/epoxy nanocomposites under tensile and torsional loadings were simulated. First, a micromechanical method was used to simulate the tensile stress-strain curve of nano phased polymer composites. Then, using the tensile stress-strain curve of the nano phased polymer and using a finite element method, the shear properties of nanocomposites are predicted. Three weight fractions 0.15, 0.25 and 0.40 wt.% of carbon nano fibers (CNFs) were considered and an experimental program was conducted to validate the present approach. The experimental results indicated that employing carbon nano fibers improves tensile and shear mechanical properties of the neat epoxy. The maximum improvements in tensile and shear mechanical properties of the neat epoxy are achieved by adding 0.40% and 0.25 wt.% of the CNF, respectively. Moreover, a comparison between predicted and experimental results shows a good agreement.