Boundary element analysis of fatigue behavior for CFRP-strengthened steel plates with center inclined cracks

This paper presents a numerical study on the stress intensity factor (SIF) and fatigue behavior of carbon fiber-reinforced polymer (CFRP) strengthened steel plates with center inclined cracks under uniaxial tensile fatigue loading. Effects of prestress level in CFRP and initial crack inclination angle were investigated. Results indicated that the CFRP laminates could reduce the mode I SIF and effective SIF range, thereby enhancing the fatigue life of the steel plates. The strengthening was more efficient by using the prestressing technique. It was found that fatigue life was approximate for specimens with an identical crack projection length on the plane perpendicular to the load. This indicated that the effect of the initial crack inclination angle on the fatigue crack propagation life of the steel plate was limited when subjected to a unidirectional load. The findings of this study can be adopted as a reference for the repair of existing metallic structures with inclined cracks.