Seismic responses of infill walls with sliding joints and openings in semi-rigid steel frame

Abstract

Forming door and window openings in partition infill walls is a frequent activity in engineering practices, while the complexity of the mechanical behavior of such infill systems with openings due to the destructive damage to the infill walls has not been thoroughly considered. To protect the vulnerable door and window openings and mitigate the detrimental multiple diagonal struts effect of infill around the opening, the paper presents two novel precast infill walls with sliding joints and door and window openings for semi-rigid steel frames. The quasi-static cyclic tests are performed on three specimens: a reference bare steel frame and two infilled steel frames with door or window opening. Test results confirm that the developed infill systems effectively prevent potential cracking or deformation of the openings and release the adverse multiple diagonal struts effect of infill with a door or window opening. Because of the working mechanism of the developed infills, the two infilled steel frames behave with similar seismic responses to the bare steel frame, while the novel infills are significantly undamaged and no detectable opening deformation is observed even at the inter-story drift ratio of 3.33%. Furthermore, both experimental and numerical responses of the developed innovative infill systems confirm the effectiveness of the infill systems without any additional fixtures to protect the fragile door and window openings.