Experimental study on fatigue behavior of CFRP strengthened steel plates subjected to marine environment

This paper presents an experimental study on fatigue performance of cracked steel plates repaired with carbon fiber-reinforced polymer (CFRP) laminates subjected to marine environment. Specimens were exposed to salt fog spray and static loading for up to 180 days. Afterward, fatigue behavior of the steel plates was tested in the room condition. Variables including the initial damage degree, repair scheme, exposure duration, and surface treatment were considered. Test results showed that the improvement in fatigue life provided by CFRP ranged from 1.65 to 45.34 times. Although the enhancement was successfully maintained in over half of the specimens even after the exposure to the harsh environment, around 40% of the samples exhibited reduction in the fatigue life, especially those with a high initial damage of 40%. Furthermore, the exposure to the marine atmosphere caused the progressive occurrence of adhesion failures.