8. Identification of Aerodynamic Properties of Bridge Decks in Arbitrary Motion

Flutter, buffeting response and vortex shedding are crucial factors when designing long-span bridges. An analysis of these phenomena requires experimental data, which can be provided by wind tunnel tests. The forced vibration method is chosen in this study because it is considered to be more reliable and better suited to provide data at high velocities, large amplitudes and more intense turbulence. The models currently used to describe self-excited forces in bridge engineering are linear. However, it is a well-known fact that the principle of superposition does not hold in fluid dynamics. Several case studies have shown that it is a fair approximation when predicting wind-induced dynamic response of bridges if the response is dominated by one vibration mode in each direction. Yet, it is uncertain how well the current models will be able to predict the self-excited forces for a more complicated motion. Currently developing experimental setup will enable the performance of forced vibration tests by applying an arbitrary motion. This paper focuses on extending three identification methods developed for single harmonic motion such that they can be applied in more complex motion patterns. Numerical simulations of forced vibration tests were performed to test the performance of those extended methods.