Repairing Behaviors of Cracked Steel Plates Based on Bolted Fiber-Reinforced Polymer Plates

The use of FRP materials to repair cracked/damaged steel structures has gradually been adopted by researchers. This paper investigates the repairing effect of bolted FRP plates for cracked steel plates based on experimental and numerical simulation methods. In the experimental investigation, the tensile strengths of six specimens, including three repaired specimens and three pure cracked steel specimens, were evaluated. The test outcomes indicated that the bolt repairing method significantly enhanced the tensile strengths of the cracked steel plates. As an example, the failure of a pure steel plate with a 1 mm width crack occurred at 813 N, whereas after being repaired, a tensile strength of 1298 N was observed. Based on finite element (FE) analysis, the influence of bolt preloads and interfacial friction coefficients were verified. The stress-relative ratio for specimens was contingent on the bolt preload magnitude and gradually decreased as the preload was augmented. By exploring the repairing effect for varied friction coefficients, it was concluded that using a higher bolt preload can aid in eliminating the performance discrepancy of the overall component caused by interface treatment errors.