Vibration characteristics of channel steel-concrete composite girders: An experimental and numerical analysis

The broad application of steel and steel-concrete bridges has caused significant vibration and noise problems. Although the channel steel-concrete composite girder is a commonly used bridge type, the vibration transmission performance and structural optimization design (concrete deck, stiffeners, transverse connection components, etc.) from the perspective of vibration control have not been well studied. In this paper, experimental and numerical approaches are combined to investigate the dynamic properties of a steel-channel girder in the audible frequency range (20–2000 Hz). A steel-channel girder is tested via hammering. The effects of damping, stiffeners, and a concrete deck on structural vibration are evaluated using the finite element method. The experimental results indicate negligible differences in the vibration responses on a single plate, but large differences at different sections. The results are influenced by the effects of the distance and transmission path. The numerical results reveal that increasing the damping and stiffness (e.g., setting stiffeners) are both effective in reducing vibrations. Furthermore, increasing the stiffness has a more prominent effect on structural vibrations and their frequency dependence, whereas increasing the damping ratio can stably reduce structural vibrations. The simulation results indicate that installing a concrete deck is the most effective approach to vibration reduction, as it can decrease overall vibration by more than 10 dB. Vertical web stiffeners have stronger effects on vibration reduction than other stiffening countermeasures (e.g., transverse connection components and longitudinal bottom plate stiffeners).