Numerical simulation of CFRP strengthened steel plates with edge cracks

Fatigue damage is a major concern for steel structures. Recently, bonding repair technique using carbon fibre reinforced polymer (CFRP) materials has demonstrated its potential for fatigue crack repair of steel members in comparison with traditional retrofitting methods. Extensive research has been carried out to investigate the improved fatigue behaviour of damaged steel elements repaired by CFRP materials. In terms of numerical simulation, limited attempts were performed to simulate the fatigue crack propagation process of defected steel members. This paper presented a boundary element analysis of CFRP strengthened steel plates with edge cracks. Three dimensional boundary element models were established based on the configuration of tested specimens in the literature. A through thickness crack was set at the edge of the steel plate to model the initial slot. Thereafter, the crack propagation was performed with NASGRO 3 law and strain energy density criterion. The numerical results matched well with the test data, including variables of initial crack length, bond configuration and number of bond layers. It was therefore concluded that the boundary element method was reliable to predict the fatigue crack growth life of edge cracked steel plates strengthened with CFRP laminates.