CFRP Repair of Steel Beams with Various Initial Crack Configurations

Abstract

This paper presents an experimental program to study the behavior of notched steel beams repaired with carbon-fiber-reinforced polymer (CFRP) sheets. Particular attention is paid to examining the interaction between the level of initial damage (i.e., notch depth) and CFRP repair. Multiple stages of fatigue-crack-propagation in a steel beam are simulated by various notch sizes, including a0/h ratios=0.1, 0.3, and 0.5 in which a0= notch depth; and h = beam height. A modeling approach is proposed to simultaneously take into account crack-propagation across the steel section and debonding of the CFRP. Efficacy of the CFRP repair is more pronounced when the damage level increases. CFRP sheet stabilizes the crack mouth opening displacement of the repaired beams until significant debonding takes place. The level of initial damage affects the behavior of a plastic region above the notch tip, the rate of web fracture, and the initiation of CFRP debonding. The damage, however, does not influence the failure mode of...