University of Twente Student Theses
An investigation into effects of temperature distribution on structural dynamics of bridges : A Comparative Study of Finite Element Methods and Field Data
Gazidede, B. (2024) An investigation into effects of temperature distribution on structural dynamics of bridges : A Comparative Study of Finite Element Methods and Field Data.
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| Abstract: | The aging infrastructure has accelerated the engineers’ efforts to update the structural health evaluation frameworks by adapting to the ever-changing spatial and temporal parameters such as temperature distribution. Long-term monitoring studies consistently highlight the impact of temperature on bridge behavior. Solar radiation, the primary driver of temperature conditions, depends on the seasonal and diurnal sun trajectories, weather conditions, bridge positioning, and surrounding objects. The confluence of these parameters causes variations in the temperature distributions in bridges, necessitating a component-based measurement, conducted by a system of sensors attached to the deck, cables, girders, etc. This BSc research investigates the temperature effects on the bridge dynamic response using a comparative study between field data and finite element methods (FEM). This study examines the UT Campus bridge by extracting five temperature scenarios describing distinct bridge conditions from a temperature analysis of historical data. The bridge’s main dynamic parameters (natural frequencies and mode shapes) are evaluated based on the Fast Fourier Transformation (FFT) of acceleration data collected in a controlled environment experimentation. Numerical replicas of the bridge using finite element modeling software (ANSYS) are used to approximate bridge dynamic behavior. With the objective of this research to investigate temperature-induced effects, two main modeling input parameters are determined: the bridge properties including geometry, material characteristics, boundary conditions, and the temperature distribution in the bridge. The predefined bridge material properties and geometry are refined through model updating techniques to match the bridge dynamic parameters. Meanwhile, the temperature scenarios are adopted to characterize bridge thermal conditions, with temperature as a force exerted in the elements of the FE model. The simulated frequencies from the FEM are compared to the observed frequencies from the scenario-based acceleration data via statistical and modal error indicators. Conclusively, the FEM predicts the trend of change; a decrease in eigenfrequency as the average temperature increases, while not missing the impact of temperature variability in the structure to play a significant role. Nevertheless, it is significantly less sensitive to the rate of change compared with the observed data. Future research on transient thermal analysis alongside scenario-based controlled experimenting for the observed data can reduce the data uncertainties as well as increase the resolution of the dynamic loading interaction in bridges. |
| Item Type: | Essay (Bachelor) |
| Faculty: | ET: Engineering Technology |
| Programme: | Civil Engineering BSc (56952) |
| Link to this item: | https://purl.utwente.nl/essays/100069 |
| Export this item as: | BibTeX EndNote HTML Citation Reference Manager |
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