Javad Vaseghi Amiri - Professor, Babol Noshirvani University of Technology, Babol, Iran
Mahdi Kiani - PhD Student, Babol Noshirvani University of Technology, Babol, Iran

Tuned Mass Damper (TMD) is a convenient passive device that is used in many structures. However, with all pleasant characteristics, there are some limitations with its performance, specifically against broad band excitations. Various approaches are proposed to dominate these drawbacks that among them using the restoring force of nonlinear springs is identified as an effective method. As materials with nonlinear force deformation curve, shape memory alloys (SMA) have brilliant stable features and significant hysteresis loops. This paper using a SMA spring with the shape memory effect presents a new TMD named as MSMA-TMD which can be developed by adding a SMA spring to a linear conventional TMD. The modified TMD has been used to control responses of a single degree of freedom structure under a harmonic excitation and by this the effect of the loading amplitude on the control of structural responses is examined. Then, the damper has been applied to control the seismic responses of single degree of freedom structures in order to compare its performance under broad band seismic excitations with the performance of conventional TMDs. The results indicate that the characteristics of the SMA can adequately control the detrimental effect of variations of the loading amplitude on the performance of MSMA-TMD. Also, the presence of hysteretic damping can significantly improve the control of seismic demands of single degree of freedom structures in comparison to common TMDs provided that dynamic properties of MSMA-TMD take their optimal values

Tuned mass damper, Shape memory alloy, Optimal design, Hysteretic damping