Analysis of wind and response measurement data from a suspension bridge
Master thesis
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https://hdl.handle.net/11250/3088415Utgivelsesdato
2023Metadata
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- Studentoppgaver (TN-IER) [147]
Sammendrag
The Lysefjord Bridge is a suspension bridge at the entrance to the Lysefjord insouth-western Norway at which full-scale measurements on wind conditions andbridge response are collected using anemometers and accelerometers. In this workPython is used to develop a toolset for analysing the wind and responsemeasurement data from the Lysefjord Bridge. The functionality is provided throughdifferent methods compiled in a class. This includes methods for importing andcombining data from multiple days, re-arranging and interpreting the data, featureengineering, data cleaning, filtering and various types of visualisations. The code isdemonstrated in an analysis of 30 days of data. The analysis focuses on the windconditions for south-westerly and north-easterly winds in terms of wind speeds,primary directions, turbulence intensity and angle of attack as well as the bridgeslateral, vertical and torsional wind response. The analysis shows on average slightlyhigher wind speeds, lower turbulence intensities and higher angles of attack forsouth-westerly winds, compared to north-easterly winds. Towards the southern endof the bridge the wind direction has a south tendency for south-westerly winds andnorth tendency for north-easterly winds. Turbulence intensity is measured slightlyhigher on the downwind side of the bridge. The angle of attack is straightenedtowards 0° on the downwind side. Furthermore, the analysis shows that theassumption of a linear correlation between drag coefficient and angle of attack usedin the so-called quasi-steady theory of wind loading and the corresponding numericalsimulations underestimates most of the larger lateral bridge responses at angles ofattack above 0°. The lift and moment coefficients estimated using similar linearityassumptions overestimate some of the larger vertical and torsional bridge responsesat angles of attack above +5°.