Acoustic black hole structures for vibration reduction of orthotropic steel bridge decks

Steel bridges are extensively utilized due to their superior mechanical properties and consistency with sustainable development objectives. However, the challenges of vibration and structure-borne noise induced by moving vehicle loads remain unresolved. This study presents a vibration mitigation concept for steel bridges based on the acoustic black hole (ABH) theory, in which variable-thickness U-rib stiffened panels are treated as ABH structures. Considering the periodic arrangement of U-ribs, the finite element method is employed to examine variations in vibration bandgap characteristics and attenuation performance across different frequency ranges. The results demonstrate that, compared to equivalent uniform-thickness U-rib panels of identical mass and rib height, the ABH-U rib stiffened panels broaden the overall bandgap width and modify the bandgap distribution. The ABH-U plates exhibit significant vibration reduction both within and beyond the band gaps. Parametric analysis indicates that tuning the structural parameters of ABH-U plates enables customized vibration control within specific frequency ranges. Among these parameters, the maximum thickness of the variable-thickness U-rib exerts a strong effect on vibration suppression. A case study on a practical steel box-girder segment shows that incorporating ABH-U ribs into the steel box girder achieves measurable vibration reduction across both bandgap and full frequency ranges, with particularly remarkable performance in controlling transverse vibrations. Proper design of U-rib parameters ensures more desirable vibroacoustic performance within the targeted frequency bands.