Surface Crack Propagation Rules of CFL-Strengthened Steel Plate under Fatigue Loading

Abstract

Steel is a kind of common materials in construction. Surface crack in steel components can reduce the bearing capacity and durability of steel structures, so it is important to strengthen the steel components with crack defects. Strengthening with fiber reinforced polymer (FRP) is a reliable reinforcement method to improve structural mechanics properties. This paper presents an experimental study on surface crack propagation rules. Carbon fiber laminate (CFL) is adopted to strengthen X80 steel plate with a semi-elliptical surface pre-crack. Specimens are tested under cyclic bending load and fatigue lives, crack lengths and depths in various stages, and crack propagation rates are discussed.