Influence of the Shape Memory Alloys on Endplate Connections and ResidualDeformation

Yielding in steel structures dissipates seismic energy, which results in residual deformations. Conventionallateral-resisting systems provide appropriate seismic safety. However, these systems undergo severe structuraldamage when exposed to strong ground motions. Seismic residual drifts make it difficult or impossible to fixdamaged structures. Therefore, systems that can reduce seismic residual deformations are required.Superelastic shape memory alloys (SMAs) can withstand significant deformations and recover all plasticdeformations upon unloading. They can significantly lessen seismic residual deformations in steel structures,making post-seismic retrofitting easier. This paper will compare the use of a superelastic Ni-Ti alloy and a FebasedSMA in two endplate connections of NIST benchmark buildings. In addition, some features that lead todecreased residual deformation in these types of joints will be investigated.

Keywords:

Shape memory alloys , Superelastisity , Finite element method , self-centering , Endplate connection , Residual deformation.