Measured dynamic properties for FRP footbridges and their critical comparison against structures made of conventional construction materials

Wei, Xiaojun; Russell, Justin; Živanović, Stana; Mottram, J. T.

doi:10.1016/j.compstruct.2019.110956

Cited by 65 publications

(59 citation statements)

References 34 publications

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“…For both footbridges with the GFRP slabs the damping ratio was assumed on the basis of literature. A comprehensive study of dynamic properties of eight FRP footbridges [ 8 ] shows that these structures have usually higher damping ratios, especially for the first vertical mode, than those made of traditional materials. The damping ratios of the investigated FRP footbridges are located in the range from 0.4 to 7.9% with the mean value of 2.5%.…”

Section: Resultsmentioning

confidence: 99%

“…The damping ratios of the investigated FRP footbridges are located in the range from 0.4 to 7.9% with the mean value of 2.5%. Authors investigated two suspension footbridges with FRP decks (Wilcott Bridge, 53.1 m long and Halgavor Bridge, 47 m long) [ 8 , 46 ]. The Wilcott Bridge was reported to have a damping ratio of 2.5% for the first vertical mode and significantly lower values, from 1.0 to 1.9%, for the higher vertical modes.…”

Section: Resultsmentioning

confidence: 99%

“…The most recent state-of-art research on FRP footbridge dynamics is presented in [ 8 ]. The authors measured dynamic properties and considered experimental works of other authors of a large set of FRP as well as conventional pedestrian bridges (138 objects in total).…”

Section: Introductionmentioning

confidence: 99%

“…Generally, FRP footbridges are recognized to be more responsive to human-induced dynamic loading than conventional structures. It is stated that the maximum accelerations of FRP footbridges can be even 3.5 times higher than those of conventional footbridges of similar geometry [ 8 ]. However, according to vibration serviceability design guidelines for footbridges [ 21 ], excessive vibration will not occur if a footbridge has a fundamental vertical frequency above 5 Hz.…”

Section: Introductionmentioning

confidence: 99%

“…As FRP footbridges are so sensitive to pedestrian-induced dynamic loading, high probability appears that their modes could be responsive to excitation by higher harmonics of the moving force. The authors of [ 8 ] conclude that for these reasons the minimum frequency limit suitable for conventional footbridges might be not appropriate for FRP footbridges.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Vibration Serviceability of Footbridges: Classical vs. Innovative Material Solutions for Deck Slabs

et al. 2020

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In this study, the human-induced dynamic performance of modern footbridges equipped with either classical reinforced concrete (RC) or innovative glass fiber-reinforced polymer (GFRP) composite deck slabs were investigated and compared. The numerical studies were carried out for two bridges: a three-span cable-stayed footbridge and a three-span continuous beam structure. Two variants of both bridges were taken into consideration: the footbridges equipped with traditional RC slabs and the structures benefitted with GFRP slabs. The risk of resonance as well as the vibration serviceability and the comfort criteria assessment of the footbridges with different slab materials were assessed. The investigation revealed that the footbridges, both cable-stayed and beam, benefitted with the GFRP slabs had higher fundamental frequency than those with the traditional RC slabs. The footbridges with the GFRP slabs were less exposed to the resonance risk, having fundamental frequencies above the limit of the high risk of resonance. The effect of shifting up the natural frequencies by introducing GFRP slabs was more remarkable for the lightweight beam structure than for the cable-stayed footbridge and resulted in a more significant reduction of the resonance risk. The calculated maximum human-induced accelerations of the footbridges benefitted with the GFRP slabs were meaningfully higher than those obtained for the footbridges with the RC slabs. The study proved that, with the same GFRP slab, meeting vibration serviceability and comfort criteria limits in the case of very lightweight beam structures may be more problematic than for cable-stayed footbridges with more massive structural systems. In the research, particular attention was paid to examining the impact of higher harmonics of the moving pedestrian force on the structures benefitted with the GFRP composite slabs. It occurred that in the case of footbridges, both cable-stayed and beam, equipped with the RC slabs higher harmonics of human force did not play any role in the dynamic performance of structures. However, in the case of the footbridges benefitted with the GFRP slabs, the impact of higher harmonics of the pedestrian force on the dynamic behavior of structures was clearly visible. Higher harmonics excited accelerations comparable to those executed by the first harmonic component. This conclusion is of great importance for footbridges equipped with GFRP slabs. The fundamental frequency may place a footbridge in the low or even negligible risk resonance range and the higher frequencies corresponding to vertical modes may be located above the limit of 5 Hz that ensures avoiding resonance. Nevertheless, the fact that fundamental modes are so responsive to higher harmonics significantly increases the risk of resonance. The amplification of the dynamic response may occur due to frequencies related to second or third harmonics (i.e., being half or a third of the natural frequencies). In such cases, full dynamic analysis of a footbridge at the design stage seems to be of crucial importance.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Vibration Serviceability of Footbridges: Classical vs. Innovative Material Solutions for Deck Slabs

et al. 2020

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Parametric design and dynamic analysis of a hybrid steel‐FRP bridge.

van IJselmuijden,

van Schaik,

Cornelissen

et al. 2023

ce papers

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In Gothenborg, Sweden a new pedestrian bridge was needed. In the proposed design, the bridge was composed of a Fiber‐Reinforced Polymer (FRP) deck and a main steel structure, which provided two intermediate supports to the deck. The design of the main steel structure was the responsibility of Systra AB in Sweden, while the FRP deck was designed by Royal HaskoningDHV in the Netherlands. The main design challenge met was the dynamic behaviour of the bridge due to human induced vibrations. Besides the technical challenges, there were also challenges to find a reliable and efficient way to for the two companies to collaborate while in two different countries. To accommodate these challenges, it was decided to create a parametric coordination model, in Rhino/Grasshopper, from which the design and calculation models were generated. This coordination model served as the single source of truth ‐ ensuring that at any time both companies had an up‐to‐date version of the model. This proved crucial as the dynamic behaviour of the bridge was significantly influenced by the interaction between the steel and FRP components. Due to the parametric nature of the model, a variation study was possible, where a total of 200 variants were produced to find an optimal design.

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Formulation of human–structure interaction for vibration serviceability of steel–concrete composite floors

Cao

Chen

2020

Struct Control Health Monit

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Summary In this paper, an analytical model representing the human–structure interaction (HSI) system of steel–concrete composite floors under human vibrations is described and discussed. In the theoretical analysis, the human and composite floor are idealized as the subsystems represented by a linear oscillator model and the anisotropic rectangular plate, respectively. The analytical formula for the natural frequency and acceleration response of a steel–concrete composite floor with various boundary conditions and HSI is proposed. For analyzing the natural frequencies, the human subsystem can be treated as a structural system with added mass, damping, and stiffness. The proposed analytical solution on the acceleration response is based on the combined weighted residual and perturbation method, which is simple to be implemented and can avoid the cumbersome numerical calculations. The theoretical solutions are validated with the experimental results. A sensitivity study utilizing the analytical solution was also conducted to investigate the effects of walking frequency, occupant weight, sprung mass, equivalent damping ratio, occupant natural frequency, and occupant spacing on the natural frequency and peak acceleration.

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Measured dynamic properties for FRP footbridges and their critical comparison against structures made of conventional construction materials

Cited by 65 publications

References 34 publications

Vibration Serviceability of Footbridges: Classical vs. Innovative Material Solutions for Deck Slabs

Vibration Serviceability of Footbridges: Classical vs. Innovative Material Solutions for Deck Slabs

Parametric design and dynamic analysis of a hybrid steel‐FRP bridge.

Formulation of human–structure interaction for vibration serviceability of steel–concrete composite floors

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