Flexural fatigue behavior of synthesized graphene/carbon-nanofiber/epoxy hybrid nanocomposites

• Graphene sheets were synthesized based on new technique of changing magnetic field.
• The fatigue performance of graphene/CNF/epoxy hybrid nanocomposites is investigated.
• Hybrid nanocomposites subjected to displacement-controlled flexural fatigue loading.
• 37.3-Fold improvement in fatigue life observed at a strength ratio equal to 43%.
• A unique flexural fatigue measurement setup for nanocomposites was developed.

In the present research, effects of adding a combination of synthesized graphene nanosheets and carbon nanofibers (CNFs) on the flexural fatigue behavior of epoxy polymer have been investigated. Graphene nanosheets are synthesized based on a changing magnetic field. The flexural bending fatigue life of 0.5 wt.% of graphene/CNF/epoxy hybrid nanocomposites has been considered at room temperature. The samples were subjected to different displacement amplitudes fatigue loadings. Due to the addition of hybrid nanoparticles, a remarkable improvement in fatigue life of epoxy resin was observed in comparison with results obtained by adding 0.25 wt.% graphene or 0.25 wt.% CNF into the resin. Experimental observations show that at a strength ratio equal to 43% by using 0.5 wt.% of hybrid nanoparticles; 37.3-fold improvement in flexural bending fatigue life of the neat epoxy was observed. While, enhancement of adding only graphene or CNF was 27.4 and 24-fold, respectively.