Graphene nanofillers as a player to improve the dynamic compressive response and failure behavior of carbon/epoxy composite

Abstract

Vast research has been going on to improve the mechanical performance of carbon fiber reinforced polymers composite (CFRP) when subjected to quasi-static loading but investigation and modification of their dynamic behavior are still underdeveloped. This paper presents an experimental investigation on the effect of randomly dispersed graphene nanoplatelets (GNPs) on the mechanical properties of CFRP composites under dynamic loading. Four different mass fractions of GNPs, 0%, 0.5%, 1%, and 2%, were considered in the experiments. Specimens were tested experimentally using the split Hopkinson pressure bar device (SHPB) to examine their dynamic response and damage behavior at high strain rates. During the dynamic compression tests, a high-speed camera was used to monitor and record the damage kinetics. The experimental characterization showed that the integration of GNPs has greatly influenced the dynamic response and damage mechanism of the CFRP. Composite doped with 1% GNPs demonstrates the optimum enhancement of the mechanical properties of the composite specimens and shows an increase of the dynamic characteristics and fracture resistance.

Graphene Sheets as Novel Nanofillers in Epoxy Matrix for Improved Mechanical Properties

“…The bending strength of the GNP/epoxy nanocomposites decreased peak stress and strain at break, Figures 6 and 7. This degradation has already been noted in some research [35][36][37], which has explained the poor dispersion of graphene. The formation of aggregates can cause a stress concentration.…”

Effect of GNP coating on carbon fibers on the deformation modes of composites under flexural loading

“…There are quite a few studies in which the investigation on the compressive behavior of the graphene incorporated CFRPs has been done. [13][14][15] Hu et al reported an increase of 8.1% in the residual compressive strength of multilayer graphene reinforced CFRPs after a low velocity impact test. 13 These CFRPs were made by hand layup of a graphene-epoxy mixture onto woven carbon fabrics before hydraulically pressing.…”

“…Another study investigated improvement in the dynamic compressive response of the GNP-added CFRPs through split-Hopkinson pressure bar (SHPB) test compared to control CFRPs. 14 These CFRPs were manufactured through GNPs/epoxy mixing in three-roller mixer followed by hot pressing. An optimized amount (1 wt.%) of GNPs resulted not only improvement in elastic properties but also showed reduction in delamination, intralaminar cracking and crack propagation as observed using a high-speed camera system during testing and SEM thereafter.…”

“…These CFRPs were made by hand layup of a graphene‐epoxy mixture onto woven carbon fabrics before hydraulically pressing. Another study investigated improvement in the dynamic compressive response of the GNP‐added CFRPs through split‐Hopkinson pressure bar (SHPB) test compared to control CFRPs 14 . These CFRPs were manufactured through GNPs/epoxy mixing in three‐roller mixer followed by hot pressing.…”

Dynamic Composite Materials Characterisation with Hopkinson Bars: Design and Development of New Dynamic Compression Systems

“…In order to use a one-dimensional approximation of axial wave propagation with good extraction of findings from input and output bars, isotropic materials were evaluated in traditional SHPB tests in a cylindrical shape with an L/D ratio roughly between 0.5 and 2 using different materials [9,10]. Materials, including soft polymers and biological tissues, have been tested at high strain rates using SHPB and their output signal contains less high-frequency noise in the signal because of their self-damping behaviour [11][12][13][14].…”