Carbon fiber reinforced polymer (CFRP) have excellent properties such as light weight, high strength, high modulus and high temperature resistance, and have wide application prospect in the fields of national defense, aerospace and high-end civilian products. Various methods have been exploited to modify the CF to increase the surface activity, roughness and wettability , so that the interfacial adhesion between fiber and matrix could be improved for better mechanical properties, which is helpful to meet the needs of more fields for high-performance CFRP. In this review, the recent progress of CF surface modification methods and their reinforcing effects on composites are mainly summarized. Finally, some issues of CFRP are discussed and the future trends of interfacial reinforcement research are prospected. 

Recent advances of interphases in carbon fiber-reinforced polymer composites: A review

Functionally graded material (FGM) is a class of advanced materials, consisting of two (or more) different constituents, that possesses a continuously varying composition profile. With the advancement of nanotechnology, applications of FGMs have shifted from their conventional usage towards sophisticated micro and nanoscale electronics and energy conversion devices. Therefore, the study of mechanical and vibrational properties of different FGM nanostructures is crucial in exploring their feasibility for different applications. In this study, for the first time, we employed molecular dynamics (MD) simulations to investigate the mechanical and vibrational properties of radially graded Cu–Ni FGM nanowires (NW). Distribution of Cu and Ni along the radial direction follows power-law, exponential and sigmoid functions for FGM NWs under consideration. Our results demonstrate that distribution function parameters play an important role in modulating the mechanical (elastic modulus and ultimate tensile strength) and vibrational (natural frequency and quality factor) properties of FGM NWs. The study also suggests that elastic moduli of FGM NWs can be predicted with relatively good accuracy using Tamura and Reuss micromechanical models, regardless of NW diameter. We found that Euler-Bernoulli beam theory under-predicts the natural frequencies of FGM NWs, whereas He-Lilley model closely approximates the MD results. Interestingly, FGM NWs are always found to exhibit beat vibration because of their asymmetrical cross sections. Finally, this is the first atomistic scale study of FGMs that directly compares MD simulations with continuum theories and micromechanical models to understand the underlying mechanisms that govern the mechanical and vibrational properties of FGM NWs in nanoscale.

Mechanical and vibrational characteristics of functionally graded Cu–Ni nanowire: A molecular dynamics study

Evaluation of interface strength is important in composite material design such as carbon fiber reinforced plastic. Molecular simulation, which considers aspects such as chemical structure, can be ...

https://www.tandfonline.com/doi/pdf/10.1080/09243046.2020.1791305

Evaluation of interface properties of carbon fiber/resin using the full atomistic model considering the electric charge state

Effect of different lateral dimension graphene oxide sheets on the interface of carbon fiber reinforced polymer composites

A key factor determining the performance of carbon fibre reinforced polymer (CFRP) composites is their fibre-to-matrix interactions, the interface and interphase, as these allow for the efficient transfer of stress from the relatively weak and ductile resin to the strong reinforcing fibres. The manipulation of the interface via modulation of surface chemistry has been been an active area of research with many apporaches being taken. In this work we cover efforts in this area from traditional manufacturing condition optimisations, plasma, wet chemical, and electrochemical approaches to induce favourable properties in composites. The design of molecular interactions at the interface are exceedingly difficult to determine and design, and thus, we finish this review with a section on the use of molecular dynamics to design complementary interfaces for the next generation of composites.

Carbon fibre surface chemistry and its role in fibre-to-matrix adhesion

In the case that the parameters to describe the force field, such as bond angles and charges, cannot be added to the library of a molecular dynamics (MD) simulation, self-development of the force field should be considered by performing quantum mechanics calculations and/or utilizing an automatic parameter generation tool. However, these techniques are not suitable for macromolecules with a large number of atoms. Typically, the force field of an oligomer containing three unit structures (a unit at both ends and a repeating unit at the center) is calculated and converted to polymer form (both ends + central part × n). Considering this, we recently developed the program o2p, which is a semi-automated program designed to set up the force field for polymers with repeating structures. However, it is difficult to apply this method to macromolecules with complex repeating structures. Thus, in this project, we developed PolyParGen, a new open-source automatic force field generation program for Gromacs that can relatively easily and reliably simulate the MD of complex macromolecules. The proposed program (1) divides the structure of the polymer into substructures with a number of atoms within the limit of the handling size for the automatic parameter generation tool program; then, (2) acquire the parameters for each divided substructure, and finally, (3) combine the parameters of these substructures to obtain the parameters for the whole polymer. By automating these processes, it is possible to acquire a parameter of a polymer having complicated structures. This program was evaluated by simulating the polymers P3EHT and F-P3EHT in chloroform. In agreement with previous reports, fluorination was found to cause F-P3EHT to adopt an extended structure, thereby indicating the effectiveness of the proposed program.

Development of PolyParGen Software to Facilitate the Determination of Molecular Dynamics Simulation Parameters for Polymers

In this study, the authors investigate the tensile strength at a carbon fiber/epoxy resin interface using molecular dynamics (MD) simulations. The simulated tension speed and strength were initiall...

Tensile test analysis of carbon fiber composite material by molecular dynamics simulation

Development of PolyParGenv2 Software for Determination of Molecular Dynamics Simulation Parameters for Molecules with Crosslinked or Condensed Ring Structures

Makoto Yabe

Papers

Development of PolyParGen Software to Facilitate the Determination of Molecular Dynamics Simulation Parameters for Polymers

Evaluation of interface properties of carbon fiber/resin using the full atomistic model considering the electric charge state

Tensile test analysis of carbon fiber composite material by molecular dynamics simulation

Development of PolyParGenv2 Software for Determination of Molecular Dynamics Simulation Parameters for Molecules with Crosslinked or Condensed Ring Structures

Distributed Processing Method on the Calculationfor the Search of All Solution