FE modeling of CFRP-repaired RC beams subjected to fatigue loading

A constitutive model is developed for fiber-reinforced polymer (FRP)-to-concrete bond for fatigue loading. The model is verified against available test data with a framework developed for further calibration as new data becomes available. The formulation is incorporated into a finite-element program and the fatigue behavior of FRP-repaired reinforced concrete (RC) beams is analyzed. Comparing the finite-element model results with test data shows that the model is capable of accurately predicting the overall cyclic fatigue loading response of RC members strengthened with FRP composites. The model is also able to capture the change in the peak deflection, the FRP plate strain development and distribution with increasing load cycles, and the number of load cycles to failure. The need for more tests on FRP-to-concrete bonded interfaces subjected to fatigue loading is identified, as is the need to measure key modeling parameters from such tests