Fatigue damage analysis of reinforced concrete column considering low-cycle behavior of HRB400 steel

In this study, a damage model-based fatigue behavior is proposed. To consider the fatigue behavior of steel in the damage model, the experimental research on reinforcing steel bar grades HRB400 was presented. The monotonic tension test and low-cycle fatigue test were carried out. The plastic strain amplitude-fatigue cycle (epsilon(p)-2N(f)) curve and plastic strain amplitude-strength loss factor (epsilon(p)-phi(SR)) curve were obtained. The fatigue parameters (C-f, C-d, and alpha) were proposed by nonlinear fitting. The specimens were simulated using the Reinforcing Steel material in OpenSees program. These fatigue parameters were proved to accurately describe the fatigue behavior of HRB400 rebar. Moreover, to verify the application of fatigue damage model in RC column, fiber-based element models were established based on the quasi-static cyclic test on RC columns. The calculated results agreed well with those of the tests. The damage degree of RC column was calculated by the recorded stress-strain curves of material. The proposed fatigue parameters could be referred in damage model based on material fatigue behavior.