Analysis and design of a hybrid re-centring energy dissipation device for steel moment frames

In earthquake resistant design, limiting elastic and inelastic deformations and maximising energy dissipation are important design considerations. In this paper, the numerical modelling, application and design of a device that makes use of the hysteretic response of shape memory alloys (SMA) and energy dissipative capability of a viscous fluid damper for energy dissipation and the superelasticity effect of SMA for re-centring are presented. After the basic workings and numerical modelling of the device are described, a design procedure based on a modified equivalent lateral load method is introduced. A design example is then given to demonstrate that the proposed device can effectively reduce peak interstory and peak top story drifts for a four-story moment frame subject to strong ground motions from 6.28% and 4% to 0.90% and 0.77%, respectively; as well as decrease the residual interstory and residual peak story drifts from 4.34% and 2.3% to 0.12% and 0.14%, respectively.