Shape memory alloys (SMAs) are characterized by unique superelastic behaviour which enables the material to recover its original shape after experiencing large deformations. This phenomenon provides ideal recentring capabilities which can be used in the passive control of structures subjected to earthquakes. However in seismic applications, the hysteretic properties of the material play an important role in determining the structural response. Research has shown that the hysteretic properties of SMAs are highly dependent on the chemical composition, the manufacturing process, and the loading strain rate. This paper focuses on investigating the effect of variability in the hysteretic properties of superelastic SMAs when used as passive control devices in structures subjected to earthquakes. The hysteretic properties of SMAs are assumed to be defined by three independent parameters. A sensitivity analysis and two case studies are conducted to examine the effect of variability of each parameter on the effectiveness of SMAs as restrainers for bridges and bracings for buildings. The outcomes of the studies show that the slope of the SMAs hysteresis has similar effect on the structural response (less than 10% in average) regardless of the type of SMA application. However, the effect of changing the hysteretic height is more pronounced in the case of SMA bracings compared to SMA restrainers. This illustrates that, in general, superelastic SMAs are relatively stable in their effectiveness in various structural applications despite the changes in their hysteretic properties.
- Shape memory alloys
ASJC Scopus subject areas
- Civil and Structural Engineering
- Building and Construction
- Mechanics of Materials