INVESTIGATION OF FLUTTER BY TWO NUMERICAL SIMULATIONS ANALYSIS FOR SUSPENSION BRIDGES

Abstract

This paper introduces two methods for calculating the critical wind speed of flutter for Great Belt East Bridge. The first method is the Computational Fluid Dynamics (CFD) by secondary development of Ansys Fluent 14.5, establishing two-dimensional bending and torsional fluid-structure interaction (FSI) numerical model. The second method, is Discrete Vortex Method (DVM) to get flutter derivatives by forced-motion for two cases, the first using only the traditional derivatives Ai and Hi for i=1-3 and the second including the two derivatives, A4* and H4*. Additionally, a realizable (κ-ε) model with enhanced wall treatment turbulence model has been considered to verify its performance in bridge aerodynamics problems. Modal analysis is also carried out to calculate the natural frequencies. It has been found that static aerodynamic coefficients have been correctly modeled using a steady simulations, while the flutter critical wind speed is judged from the time history of unsteady simulations for stationary deck sections. The validity of the simulation methods were verified by comparison of the simulation results with the work done by other researchers and it found that the results are in good agreement.