Study on in-plane/out-of-plane seismic performance of opening infill wall-RC frame structure with a new type of flexible connection

Abstract When an earthquake occurs, the seriously damaged infill walls have an adverse impact on frame due to infill-frame interaction. Some codes suggest that the infill walls should be isolated from frames or use a flexible connection construction, but these applications may reduce OOP (out-of-plane) stability and increase the risk of OOP collapse. In this study, a new type of flexible connection is adopted for the opening infill wall-RC frame structures. The infill wall-RC frame structures with rigid connection, traditionally flexible connection and new type of flexible connection in this context were examined experimentally and numerically, and their IP and OOP after IP (in-plane) damage seismic performance were compared. As a result of the study, the new type of flexible connection effectively reduces IP damage of the infill walls and undesirable infill-frame interaction. Compared with rigid and traditional connection, the frame with new flexible connection improves the energy dissipation capacity by about 37.8% and 3.5%, respectively. At the same time, the OOP strength and stiffness of the new flexible connection increased by 119.8% and 104.2% in the same prior IP drift ratio than that of traditional flexible connection. It is thought that the steel cable structure can improve the restraint of frames on infill walls, which is beneficial to development of OOP horizontal arch mechanism.