Evaluating Wind Loads on Bridge Decks Using Velocity Fields

AbstractThe wind loads including forces and moments on bridge decks are evaluated in the current study using the velocity fields and their derivatives. Based on the conservation of momentum and momentum moment, the integral over the control volume is converted to the surface integral over the boundary of the control volume using the divergence theorem. The wind forces and moments can be calculated based on the obtained velocity fields and their derivatives around bridge decks, and the pressure terms in the equations are canceled out. Velocity fields are obtained from computational fluid dynamics (CFD) simulations and particle image velocimetry (PIV) wind tunnel experiments. Results from different turbulence models are compared with each other and wind tunnel experimental results in the literature. The calculated wind loads from numerical integrations of velocity fields from PIV experiments or CFD numerical simulations are compared with the results from a direct integration of the CFD-simulated surface pressure and the results from force-balance measurements in the wind tunnel. The results from several cases with different sizes of control volumes and space resolutions for both the square cylinder section and the twin-box girder section are discussed.