Effects of arrangement and shape of MWCNT and GNP reinforcements on nanocomposite mechanical properties

Abstract

In this investigation, multi-walled carbon nanotubes (MWCNTs) and graphene nanoplatelets were used to prepare two-phase and hybrid epoxy-based nanocomposites. Tensile and compressive mechanical properties of nanocomposites containing different amounts of MWCNTs and graphene nanoplatelets were determined using experimental, micromechanical, and numerical methods. Moreover, micrographs from samples’ fracture surfaces were obtained using field emission scanning electron microscope. Numerical simulations were carried out to investigate the effects of aligned and randomly distributed straight and sinusoidal MWCNTs and graphene nanoplatelets weight fraction on nanocomposite mechanical properties. To achieve our goals, three different sets of models consisting of MWCNTs, graphene nanoplatelets, and hybrid nano-fillers were analyzed. First, six different models consisting of aligned hybrid nanocomposite were analyzed to investigate the effect of arrangements of MWCNTs and graphene nanoplatelets on nanocomposites Young’s moduli. Then, models containing sinusoidal nano-fillers were generated based on the arrangement of the aligned model which had the best correlation with experimental measurements. Also, more realistic nanocomposite models consisting of randomly distributed straight nano-reinforcements were created to investigate the effects of reinforcement distribution on nanocomposite properties. To examine the accuracy of numerical simulations, Halpin–Tsai micromechanical method modified for hybrid nanocomposites was used. Numerical results were compared with micromechanical predictions and experimental measurements and good agreement was observed.

Experimental assessment of adding carbon nanotubes on the impact properties of Kevlar-ultrahigh molecular weight polyethylene fibers hybrid composites

“…The results of these phenomena can be seen in the form of the delamination of Kevlar fibers and expanding the damage area on the surfaces of composites. By adding 0.1 wt.% CNTs, a part of energy can be wasted by pull-outing, bridging, and fracturing the CNTs [25,26].…”

“…The CNTs can be resisted against the microcracks by bridging, pulling out, and fracturing of those, which can be seen in Figure 12. Based on other literatures [25,33], these phenomena have important role to increase the energy absorption into the composite structures. When the load was transformed to the CNTs, they can first resist by bridging the cracks’ tips.…”

Elastic modulus and Poisson’s ratio of graphene nanoplatelet/glass fiber-reinforced polymer hybrid composites subjected to off-axis loading

“…Among the nanoscale fillers, the exploitation of graphene is certainly a great current interest in producing hybrid composites. [13][14][15] Graphene shows very high elastic modulus and extraordinary fracture strength. 16,17 A wide range of mechanical properties can be attained by a suitable combination of microscale fibers, polymer matrix, and graphene nano-additives.…”

Laminate analogy approach for the effective elastic properties of metal matrix nanocomposites filled with randomly dispersed graphene nanoplatelets

“…Characterizing the Eshelby tensor is achieved by noting the geometry of the inclusions. 11,12 Many other methods such as the semi-empirical Halpin–Tsai equation or unit cell models are tools for a researcher to calculate the stiffness of nanocomposites. 13,14 Zarasvand et al.…”

“…Calculations on the elastic modulus of nanocomposites are the center of many continuum-based studies, 9–15 whereas for the strength calculation of nanocomposites, works in the literature have paid less attention. 16–20 Tserpes et al.…”