Test on fatigue repair of central inclined cracked steel plates using different adhesives and CFRP, prestressed and non-prestressed

This paper investigates the fatigue repair of 15 central inclined cracked steel plates using different repair materials and prestress levels. Thirteen steel plates were repaired with three kinds of carbon fiber reinforced polymer (CFRP) and two kinds of adhesive in different configurations (single-sided, double-sided, non-prestressed and prestressed). Two unrepaired steel plates were used as the reference. Fatigue performance was evaluated using the fatigue life and the failure mode. It was found that when the tensile stiffness of distinct CFRP was identical, the fatigue lives of different specimens in the same configuration were alike regardless of the failure mode. Nevertheless, different CFRP and adhesives contributed strongly to the failure mode. Fatigue lives demonstrated that double-sided repair was more efficient than single-sided repair, while prestressed repair had the highest repair efficiency. When prestressed, higher prestress level led to greater fatigue life improvement. Besides, prestress levels measured from CFRP strain and steel plate strain were compared; the latter was found to be more consistent with the tested fatigue lives.