Modelling nonlinear dynamic behaviour of rocking bridge piers with shape memory alloys

Abstract

In recent years, accelerated bridge construction (ABC) has led to substantial application of precast post-tensioned segmental (PPS) bridge piers. However, PPS piers are not widely used in high-seismicity regions due to their low energy-dissipation capacity. To address this deficiency, this research work examines a series of Shape Memory Alloy (SMA) concrete composite PPS piers. Nonlinear static and dynamic analyses are performed on experimentally validated Finite Element (FE) models of the SMA concrete composite piers, and the results are compared with those without SMA bars. It is found that length, area, and post-tensioning ratio of the SMA bars affect the energy dissipation capacity of the piers, and an optimal design of the bars is required to reach the highest energy dissipation possible. The effects of the SMA bars on the frequency response functions of the piers are investigated for the first time in this study, and it is shown that, unlike the piers without SMA bars, the sub-harmonics and super-harmonics are not seen in the response of the SMA concrete composite piers, mainly for the drift responses. Further, the SMA concrete composite piers experience a significant reduction in the drift responses compared to those without SMA.