Investigation of a butterfly-arch stress-ribbon pedestrian bridge under ambient excitation: dynamic identification, FE modelling and parametric optimization

The dynamic behavior of a butterfly-arch stress-ribbon pedestrian bridge located in Fuzhou, Fujian, China was investigated under ambient excitation. Highly synchronous tri-axial wireless sensors were used to get an estimate of the model parameters, finding eight stable modes with bending and torsional deformations in the frequency range 3.59–14.92 Hz. Different finite element models of the bridge were developed and a parametric optimization process with a sensitivity-based algorithm was performed to achieve the best model which could be used as baseline for a long-term monitoring of the bridge.