Aeroelastic analysis is a major task in the design of long-span bridges, and recent developments in computer power and technology have made Computational Fluid Dynamics (CFD) an important supplement to wind tunnel experiments. In this paper, we employ the Finite Element Method (FEM) with an effective mesh-moving algorithm to simulate the forced-vibration experiments of bridge sectional models. We have augmented the formulation with weakly-enforced essential boundary conditions, and a numerical example illustrates how weak enforcement of the no-slip boundary condition gives a very accurate representation of the aeroelastic forces in the case of relatively coarse boundary layer mesh resolution. To demonstrate the accuracy of the method for industrial applications, the complete aerodynamic derivatives for lateral, vertical and pitching degrees-of-freedom are

A modified rigid-object formulation is developed, and employed as part of the fluid-object interaction modeling framework from [1] to simulate free vibration and flutter of long-span bridges subjected to strong winds. To validate the numerical methodology, companion wind tunnel experiments have been conducted. The results show that the computational framework captures very precisely the aeroelastic behavior in terms of aerodynamic stiffness, damping and flutter characteristics. Considering its relative simplicity and accuracy, we conclude from our study that the proposed free-vibration simulation technique is a valuable tool in engineering design of long-span bridges.

Buffeting analysis plays an important role in the wind-resistant design of long-span bridges. While computational methods have been widely used in the study of self-excited forces on bridge sections, there is very little work on applying advanced simulation to buffeting analysis. In an effort to address this shortcoming, we developed a framework for the buffeting simulation of bridge sections subjected to turbulent flows. We carry out simulations of a rectangular bridge section with aspect ratio 10 and compute its aerodynamic admittance functions. The simulations show good agreement with airfoil theory and experimental observations. It was found that inflow turbulence plays an important role in obtaining accurate wind loads on the bridge sections. The proposed methodology is envisioned to have practical impact in wind engineering of structures in the future.

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Computational Fluid Dynamics (CFD) and Fluid-Structure Interaction (FSI) are growing disciplines in the aeroelastic analysis and design of long-span bridges, which, with their bluff body characteristics, offer major challenges to efficient simulation. In this paper we employ Isogeometric Analysis (IGA) based on Non-Uniform Rational B-Splines (NURBS) to numerically simulate turbulent flows over moving bridge sections in 3D. Stationary and dynamic analyses of two bridge sections, an idealized rectangular shape with aspect ratio 1:10 and a 1:50 scale model of the Hardanger bridge, are performed. Wind tunnel experiments and comparative Finite Element (FE) analyses of the same sections are also conducted. Studies on the convergence, static dependencies on the angle-of-attack, and self-excited forces in terms of the aerodynamic derivatives show that 1 Helgedagsrud, March 4, 2019 IGA successfully captures the bluff-body flow characteristics, and exhibits superior per degree-offreedom accuracy compared to the more traditional lower-order FE discretizations.