Seismic control of structures using shape memory alloys

There has been an increase in the use of concentrically braced frames, damage during past sesmic effects suggests that braced systems may perform poor due to limited ductility and energy dissipation, failure in the connection between the braces and the frame and asymmetric in tension and compression. One way of improving the performance of CBF systems in terms of limiting inter story drifts is the use of smart materials in the bracing system. Shape Memory Alloys (SMAs) are a novel functional material which can exhibit little residual strains under cycles of loading and unloading even after passing the yield zone. They have the ability to remember a predetermined shape even after severe deformations which enable them to be widely used in numerous applications in the area of smart materials or intelligent materials. In this study, the behaviour of steel braced frames and SMA braced frames are compared by performing time history analysis. The effect on displacement and stress distribution was analyzed and discussed. SMAs possess properties which are not present in materials earlier utilized in engineering practice. Accordingly, their use opens the possibility of designing and proposing innovative commercial products based on their unique characteristics.