SMA dampers for bridges

Both superelastic and martensitic SMAs can be used as damper elements for bridges. Li et al. [30] numerically studied an application of a superelastic SMA damper for vibration reduction of a cable-stay bridge. This SMA-cable damper system is illustrated in Fig. 9.19. The numerical simulation shows that the proposed SMA damper can effectively suppress the cable’s vibration.

In [31], the testing and simulation analysis results of a full-scale superelastic SMA bar restrainer (Fig. 9.20) used for seismic retrofit of a multi-span simply supported bridge were reported. The results have shown that the SMA restrainer more effectively reduced the relative hinge displacements at the abutment and it provided a large elastic deformation range in comparison with conventional steel restrainer cables. In addition, the SMA restrainer effectively limits the motion of the bridge decks.


Fig. 9.20 Schematic of the setup of SMA restrainer for
a simple-supported bridge [31].

Casciati et al. [1] studies an application of a large martensitic Nitinol bar as a seismic protection device in a bridge. The finite element analysis used shows the applicability of the martensitic Nitinol bar in energy dissipation in relation to both the static and dynamic response to strong earthquakes. The analysis conclusion is in agreement with the experimental results.