Superelastic SMA Dampers for Long-Span Bridges

This chapter introduces a novel passive seismic control mechanism for cable-stayed bridges using superelastic shape memory alloy (SMA) and examines its performance. A 3-dimensional (3-D) bridge model that takes soil-structure interaction into effect is equipped with SMA dampers and analyzed under ground motion excitation. The SMA dampers are installed at the deck-tower and deck-pier connections of the bridge. Three orthogonal components from two historical ground motion recordings are applied to the bridge. The study sheds light on how well the SMA dampers can mitigate deck movements and reduce the amount of shear force and bending moment demands placed on the bridge towers during strong earthquakes.