Carbon fiber–reinforced nanocomposites: a multiscale modeling of regularly staggered carbon fibers

This chapter investigates both the mechanical properties as well as stress transfer characteristics of multiscale composites comprising nano- and microscale reinforcements. To improve the microfiber–matrix interfacial adhesion, carbon nanostructures (CNS) were incorporated into the epoxy around the continuous microscale fiber. These CNS are composed of aligned carbon nanotubes (A-CNTs). First, we evaluated the effective elastic properties of the interphase layer made of CNS and epoxy in conjunction with the Mori–Tanaka analytical model using the molecular dynamics simulations. Subsequently a micromechanical pull-out model was developed for a continuous fiber multiscale composite considering different CNS orientations accounting their perfect as well as imperfect interfacial bonding with the surrounding epoxy. The outcomes obtained from the pull-out model and finite element simulations were validated and were found to be in good coherence. Our outcomes revealed that the stress transfer behavior multiscale composite is significantly enhanced by governing the CNT morphology around the fiber, specifically, when it is parallel to the microscale fiber’s longitudinal direction.