Experimental study on the fatigue behavior of CFRP-strengthened cracked steel plates under eccentric axial tension

In this paper, an experimental investigation has been conducted to study the fatigue behavior of single edge-notch steel plates strengthened with CFRP (laminates/sheets). The plates have been subjected to eccentric fatigue under axial loading conditions. The experimental study includes fourteen specimens and has been tested under axial loading until failure. The constant parameters in the study are steel material grade, steel plate dimensions, and fatigue loading conditions. Meanwhile, the studied parameters are steel plate initial edge crack size, CFRP configurations (length, one or two-sided, and laminates or sheets), and adhesive material strength. The experimental results revealed that the fatigue life for specimens strengthened with CFRP sheets or CFRP laminates can be improved by a factor of 1.15 to 3.87 and 1.47 to 6.32, respectively, compared with the un-strengthened specimens. The results show that using CFRP can be considered an efficient way to repair the initial cracks in steel elements under eccentric axial fatigue loading.