Experimental and numerical study on the hysteretic behavior of composite partially restrained steel frame-reinforced concrete infill walls with vertical slits

The work presented in this study aimed to investigate the hysteretic behavior of composite partially restrained (PR) steel frame-reinforced concrete infill walls (PSRCW) with vertical slits, which consisted of a PR steel frame, a slit-reinforced concrete (RC) infill wall, and shear connectors. An experimental program at one-third scale of a one-bay by three-story PSRCW with vertical slits was tested under horizontal cyclic loading. The seismic behavior was examined in terms of the lateral load-carrying capacity, ductility, deformability, lateral stiffness, and energy dissipation. The results showed that this kind of structure exhibited superior ductility and deformability, as well as excellent energy-dissipation capacity. The slit RC infill walls exhibited flexure-dominated behavior and significantly increased the lateral load-carrying capacity. In contrast, the slit RC infill walls decreased the rotation demand on the PR connections from earthquake, which avoided the fracture failure of the beam-to-column connection. Additionally, the test results were verified, and relative parametric analyses of PSRCW with vertical slits were conducted by using a simplified macro fiber model to illustrate the factors that influence the structural hysteretic behavior.