Study on restoring force model of fiber reinforced concrete shear wall considering damage index

Using combined theoretical and experimental regression analysis methods, the results gained from quasi-static cyclic tests on six shear walls with fiber reinforced concrete (FRC) in bottom region were investigated. A set of simplified computational formula was presented to estimate the load-displacement skeleton curves of FRC shear walls, while considering influencing factors such as the axial load ratio, ratio of longitudinal reinforcement in boundary regions, confinement index of stirrups, mechanical properties of FRC and steel reinforcement, and steel sleeve. To evaluate the effect of loading history on performance degradation of FRC shear walls, a damage model was introduced based on the fitted results of cyclic loading test data. Also, the overall seismic behaviors including unloading stiffness of hysteresis loops and residual strength on descending branch of skeleton curve were assessed quantitatively by a proposed restoring force model and hysteresis rules. It was found that the simulated hysteretic behaviors had good agreement with test results, and the feasibility of proposed restoring force model was verified.