Incremental dynamic analysis of steel frames equipped with NiTi shape memory alloy braces

This paper determines the seismic performance of four-storey concentrically braced frames equipped with either steel buckling-restrained braces or buckling-restrained superelastic shape memory alloy (SMA) braces through incremental dynamic analysis. The incremental dynamic analysis technique is used to examine the behaviour of four-storey braced frames with four different bracing configurations (including diagonal, split-X, chevron-V and inverted-V) under 20 different ground motion records. The study reveals a satisfactory performance at the design intensity level for both types of braced frames. The results show that the SMA braces lead to a uniform distribution of inelastic response over the height of the buildings, as well as mitigating seismic response in terms of maximum inter-storey drift and residual roof displacement. By comparing the responses of SMA and buckling-restrained braced frames under higher intensities of earthquake loading, it is found that the SMA braces can be more beneficial especially under severe ground motion excitations. Copyright (c) 2014 John Wiley & Sons, Ltd.