Recent advances in understanding environmental effects on degradation of carbon fiber/epoxy matrix interface in civil engineering applications via molecular simulation

In civil engineering, carbon fiber-reinforced polymer (CFRP) composite has been increasingly used in building structures, due to its excellent mechanical properties. The interface between carbon fiber and epoxy matrix is critical for the stress transfer in the CFRP, which largely determines the long-term durability of composite material. However, the fiber/matrix interface is vulnerable to the hygrothermal and salt environment, which leads to the interfacial debonding and final composite failure. In consideration of the durability issue of composite material, the interfacial degradation between fiber and matrix under environmental effects should be fully understood. Molecular dynamics simulation can provide a bottom-up description of the fiber/matrix interface in the simulated environments, which contributes to the understanding of the interfacial degradation mechanism. In this work, the recent simulation progress in understanding the environmental effects on the degradation of carbon fiber/epoxy matrix interface from a nanoscale perspective was reviewed, including the development of the interface model, the degradation of the interfacial structure and properties in various environments such as wet and salt environment, and the underlying degradation mechanism. Meanwhile, future research direction involving further development of the fiber/matrix interface model was also provided.