Seismic Response Analysis of Knee-Braced Steel Frames Using Ni-Ti Shape Memory Alloys (SMAs)

Benyamin Mohebi; Farzin Kazemi; Atefeh Yousefi

doi:10.1007/978-3-031-30125-4_21

Seismic Response Analysis of Knee-Braced Steel Frames Using Ni-Ti Shape Memory Alloys (SMAs)

Abstract

Shape Memory Alloys (SMAs) are known as active materials that can be widely ‎used for structural purposes due to their flag-shape behavior under loading and ‎reloading. Their unique characteristics provided a potential solution for civil engi-‎neers especially to model buildings with the capability of dissipating seismic en-‎ergy. In this study, the main purpose is to explore the seismic behavior of Knee-‎Braced Frames (KBFs) and use SMA materials in the knee member as the repa-‎rable member that plays a crucial role in dissipating energy. For this aim, the four, ‎eight, and twelve stories (‎i.e. 4-Story, 8-Story and 12-Story) structures with lat-‎eral resisting systems of Concentrically Braced Frame (CBF), Knee Braced ‎Frame (KBF), and a KBF ‎with SMA member (KBF-SMA) have been modelled ‎using Opensees. To validate the modelling procedure of SMA members, ‎ABAQUS software was used. Then, Incremental Dynamic Analysis (IDA) was ‎performed for seismic response assessment of structures assuming Sa(T1) as in-‎tensity measure and maximum interstory drift ratio (IDR) and residual roof drift ‎ratio (RIDR) as Engineering Demand Parameters (EDPs). The results showed ‎that the KBF-SMA system decreased the RIDR by 32.34% at given Sa(T1) from ‎‎0 to 2(g), and 41.79% at given Sa(T1) from 2 to 4(g), respectively, compared to ‎the values of CBF system. In addition, compared to the values of the KBF sys-‎tem, the RIDR decreased by 22 % at given Sa(T1) from 2 to 4(g), and 87.18% at ‎given Sa(T1) from 4 to 6(g), respectively.‎