Modal identification and damping performance of a full‐scale GFRP‐SFRSCC hybrid footbridge

Slender footbridges are prone to excessive vibrations due pedestrian effects, and comfort criteria often govern their design. In this sense, composite materials that combine high damping capacity with relatively stiffness low mass can provide functional benefits. This paper presents a study of the dynamic behaviour an 11 m long hybrid footbridge made two I-shaped pultruded glass fibre reinforced polymer (GFRP) main girders thin steel self-compacting concrete (SFRSCC) deck, in operation since 2015. The goals were (i) improve knowledge properties (ii) assess benefits using structure GFRP instead conventional material (steel), namely, considering its greater ability dissipate energy. resonant frequencies, ratios, mode shapes identified based on experimental testing. A finite element (FE) model was developed calibrated test data used simulate effects loads. Simulations same type conducted equivalent structural system profiles. simulation results short-span similar natural frequencies enhance impact high-order harmonics load response. It is also shown polymer-based components contribute limiting or even act as self-dampers.