Seismic collapse behavior of steel structures with a smart axial polyurethane friction damper

Abstract

Shape memory alloys (SMA) are utilized in various engineering fields, owing to their unique properties. In this study, the collapse behavior of steel structures designed with a self-centering damper under seismic sequences was investigated. The proposed damper was made of SMA plates, friction devices, and polyurethane springs called axial polyurethane friction (APF) -SMA dampers to provide desirable damping capabilities and good self-centering behavior. Concentrically braced 14-story steel frames using four types of bracing systems (split X, chevron V, inverted chevron IV, and diagonal) were modeled in OpenSees with and without the APF-SMA damper to evaluate their seismic resistance performance. An incremental dynamic analysis (IDA) was performed for the frames, and the maximum inter-story drift IDA curves of the frames were developed and compared. The analysis results indicated that the APF-SMA damper limited the maximum inter-story drifts of the conventional steel frames and effectively reduced the residual inter-story drifts of the braced frames. Finally, the advantages of the proposed APF-SMA over the conventional braced frames were demonstrated through probabilistic analyses of the results based on the nonlinear response history analyses.