Seismic behavior analysis for composite structures of steel frame-reinforced concrete infill wall

The composite structure of steel frame-reinforced concrete infill wall (CSRC) combines the advantages of steel frames and reinforced concrete shear walls. Reinforced concrete infill walls increase the lateral stiffness of steel frames and reduce seismic demands on steel frames thus providing opportunities to use partially restrained connections. In order to study seismic behavior and load transfer mechanism of CSRC, a two-story one-bay specimen was tested under cyclic loads. With that, the main characters such as, strength, stiffness, ductility, energy dissipation, load distribution, performance of steel frames, partially restrained connections and studs, are analyzed and evaluated. The experimental results show that the structure has adequate strength redundancy and sufficient lateral stiffness. The CSRC system has good ductility and energy dissipation capability. Partially restrained connections could enhance ductility and avoid abrupt decreases in strength and stiffness after the failure of infill walls. The composite interaction is ensured by headed studs, which have failed because of low-cycle fatigue. Steel frames bear 80%-100% of overturning moments, and the remainder is undertaken by infill walls; steel frames and infill walls resisted 10%-20% and 80%-90% of lateral loads, respectively. Furthermore, relevant design recommendations are presented. Copyright (c) 2011 John Wiley & Sons, Ltd.