Seismic performance of chevron braced frames with shape memory alloy vertical shear link

Chevron braced steel frames with vertical shear link have reliable displacement dependent dampers with sufficient strength and ductility to dissipate energy of strong earthquakes through inelastic mechanisms. In this study, shape memory alloy with its superelastic behavior is utilized as material of vertical shear link to improve the ductility characteristics of the system and decrease residual displacements in the structures due to its self-centering capability. Nonlinear time-history, incremental dynamic analysis, and dynamic pushover analysis techniques are used to investigate the behavior of two different four- and eight-story frames with steel vertical shear link (STVL) and shape memory alloy vertical shear link (SMVL) under various earthquake records. The results show that there is a negligible residual displacement in the structures with SMVL, although considerable residual displacements can be observed in the structures with STVL. For instance, when the eight-story frame is subjected to the Northridge earthquake, a 12-cm residual displacement is observed in the structures with STVL, whereas the structures with SMVL might experience just 3-cm residual displacement.