• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.4
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• pp.213-219
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• 2021

Polytetrafluoroethylene (PTFE) is a commercialized friction material in friction pendulum systems used for earthquake hazard mitigation in structures, and it has excellent chemical resistance and frictional performance. However, PTFE has a relatively low wear resistance for the friction pendulum systems in service. As an alternative to PTFE, a cost-effective frictional material, polyvinylidene fluoride (PVDF) strengthened by magnesium oxide (MgO), with enhanced wear resistance performance is proposed in this study. The frictional performance of the developed PVDF/MgO was evaluated through experiments and compared with that of PTFE. Accordingly, a friction pendulum system was designed using the measured friction coefficient. The performance of this friction pendulum system was evaluated via nonlinear time history analyses of bridges. Subsequently, the plausibility of using PVDF/MgO as an alternative to PTFE as a friction material for friction pendulum systems was discussed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.2
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• pp.105-112
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• 2023

In this study, structural analyses were conducted to analyze the performance of a bridge to which friction pendulum systems (FPSs) were applied using different friction models. A Coulomb friction model and a rate dependent friction model were constructed using the friction coefficient of a PVDF/MgO friction material to analyze the effect of different friction analysis models. The Coulomb friction model uses a single friction coefficient regardless of friction velocity, while the rate dependent friction model can reflect the change in the friction coefficient with friction velocity. Nonlinear time history and seismic fragility analyses were conducted to confirm responses of the bridge. The seismic responses of a deck and a column were used to evaluate the performance of the base isolated bridge, and a friction model that can effectively evaluate the performance of isolated bridges was analyzed.