Vortex-Induced Vibration Passive Control of Long-Span Bridges Using Shape Memory Alloy–Enhanced TMD

Vortex-induced vibration (VIV) refers to the oscillations of bluff bodies with limited amplitude due to periodic vortex shedding, which has been observed in many long-span bridges recently. This study introduces a novel nonlinear shape memory alloy–enhanced tuned mass damper (SMA-TMD) to mitigate the VIV in long-span bridges. The restoring force of the SMA-TMD is modeled as a polynomial function of temperature. The governing equations of the system are established, and the damper's parameters are optimized. The VIV suppression performance is evaluated from various perspectives, including the VIV response of the bridge deck, the stroke of the mass block, and the effects of temperature. A comparative analysis between the SMA-TMD, a TMD, and a nonlinear energy sink is also conducted. Results indicate that the SMA-TMD achieves superior VIV mitigation performance, particularly under extremely small mass ratios, and demonstrates the highest control efficiency among the three dampers examined. Based on these findings, the SMA-TMD is well-suited for vibration control in cases with small mass ratios, offering enhanced economic performance.