Fiber reinforced composites have wide structural applications and vast research has been going on to improve their mechanical performance when subjected to quasi-static loading but, study of their dynamic behavior is still underdeveloped. For this reason, scientists have been continuously working on developing methods to improve their dynamic characteristics and addition of nanofillers suchs as Carbon Nanotubes (CNTs) as reinforcement is considered a possible solution for developing future generation high-quality fiber reinforced nanocomposites. In this study, composite specimens are manufactured using Epon 862 Epoxy resin and T300 6 k carbon fibers, and each specimen contained different weight percentages of multi-walled Carbon nanotubes (MWCNTs) i.e. 0% as a reference, 0.5%, and 2%. Specimens were tested experimentally using the Split Hopkinson pressure bar device (SHPB) under different pressures 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 CNTs in matrix has greatly influenced the dynamic response and damage mechanism of the Carbon Fiber Reinforced Polymers composite (CFRP). Mechanical behavior of specimens with each percentage demonstrated the enhancement of the mechanical properties and showed the increase of the dynamic characteristics and fracture resistance because of the increase in stiffness of matrix material and interfacial bonding between matix and fiber reinforcement.

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.

Previous research has shown that nanocomposites show not only enhancements in mechanical properties (stiffness, fracture toughness) but also possess remarkable energy absorption characteristics. However, the potential of carbon nanotubes (CNTs) as nanofiller in reinforced epoxy composites like glass fiber-reinforced polymers (GFRP) or carbon fiber-reinforced polymers (CFRP) under dynamic testing is still underdeveloped. The goal of this study is to investigate the effect of integrating nanofillers such as CNTs into the epoxy matrix of carbon fiber reinforced polymer composites (CFRP) on their dynamic energy absorption potential under impact. An out-of-plane compressive test at high strain rates was performed using a Split Hopkinson Pressure Bar (SHPB), and the results were analyzed to study the effect of changing the concentration of CNTs on the energy absorption properties of the nanocomposites. A strong correlation between strain rates and CNT mass fractions was found out, showing that an increase in percentage of CNTs could enhance the dynamic properties and energy absorption capabilities of fiber-reinforced composites.

The current investigation evaluates the compressive response of 3D-printed carbon fiber-reinforced PETG thermoplastics to optimize different infill parameters when loaded at high impact pressures (strain rates). The selected parameters for the 3D printing of different samples are the filling pattern (rectilinear and honeycomb) and the filling density (25%, 50%, and 75%). Compression-split Hopkinson pressure bars (SHPBs) combined with a high-speed camera were used to monitor the evolution of the mechanical behavior and damage kinetics of 3D-printed samples in real-time with the variation in strain rate. The results revealed a significant improvement in compressive strength and compressive modulus when the filling density was increased from 20% to 75% for both patterns. However, the combination of a honeycomb pattern with 75% filling presented the best compressive strength, stiffness and damage resistance, irrespective of impact pressure. In particular, the highest compressive strengths, ranging from 35.5 to 56.16 MPa for impact pressures of 1.4 to 2.4 bar, respectively, were obtained with this configuration (75% honeycomb pattern). This represents a substantial difference of 25 to 38% compared with the 75% rectilinear pattern, which showed values below 35 MPa. Another significant result was observed for the compressive modulus, which reached 2787.8 MPa for the honeycomb-filled samples, whereas this value remained below 2000 MPa for the rectilinear pattern.