Environment-assisted degradation of the bond between steel and carbon-fiber-reinforced polymer

AbstractThis paper summarizes the environmentally assisted degradation of the bond between steel and carbon fiber–reinforced polymer (CFRP) composites through analysis of the mechanical performance of loaded and unloaded steel/CFRP double strap joints exposed to various harsh environments such as elevated temperatures, seawater, cyclic temperature and humidity, and ultraviolet (UV) radiation. It was found that both joint stiffness and strength significantly decreased by up to 80% when tested at elevated temperatures near to or greater than Tg of the adhesive used. The mechanical properties reduced by about 20% when exposed to seawater for up to 1 year. Although no significant reduction in stiffness and strength were found when the unloaded joints were exposed to cyclic temperature between 20 and 50°C with the added presence of humidity, the loaded joints catastrophically failed during the exposure, showing that the combination of load, temperature, and moisture was the most critical scenario. In addition,...