Fatigue behavior of steel plates with multi-holes repaired by CFRP

Carbon fiber reinforced polymer (CFRP) repairing is an important approach to improve fatigue performance of cracked steel structures. Based on experiment and finite element method (FEM), the crack propagation and fatigue live of CFRP repaired steel plates with multi-holes were studied. The test results showed that the fatigue life of the steel plate could be reduced by the existence of multi-holes, and after being repaired with CFRP, the corresponding fatigue life was significantly improved. The multi-holes had a considerable effect on crack propagation trajectory and fatigue life, the main influencing factors were the number and location of the multi-holes. Further finite element analysis showed that the effect of the multi-holes on crack growth was mainly related to the change of the stress intensity factors ΔKI and ΔKII.