Aeroelastic analyses of bridges using a Pseudo-3D vortex method and velocity-based synthetic turbulence generation. (1st December 2018)

• Record Type: Journal Article
• Authors: Kavrakov, Igor; Morgenthal, Guido
• Is Part Of: Engineering structures. Volume 176(2018)
• Page Start: 825
• Page End: 839
• Publication Date: 2018-12-01
• Subjects: Computational bridge aerodynamics -- Buffeting -- Flutter -- Long-span bridges -- Vortex particle method; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2018.08.093
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: A novel Turbulent Pseudo-3D Vortex Particle Method is introduced. Aerodynamic analyses of the Great Belt bridge using a reduced CFD model. Verification with the semi-analytical Linear Unsteady model in time-domain. Abstract: The accurate representation of aerodynamic forces is essential for a safe, yet reasonable design of long-span bridges subjected to wind effects. In this paper, a novel extension of the Pseudo-three-dimensional Vortex Particle Method (Pseudo-3D VPM) is presented for Computational Fluid Dynamics (CFD) buffeting analysis of line-like structures. This extension entails an introduction of free-stream turbulent fluctuations, based on the velocity-based turbulence generation. The aerodynamic response of a long-span bridge is obtained by subjecting the 3D dynamic representation of the structure to correlated free-stream turbulence in two-dimensional (2D) fluid planes, which are positioned along the bridge deck. The span-wise correlation of the free-stream turbulence between the 2D fluid planes is established based on Taylor's hypothesis of frozen turbulence. Moreover, the application of the laminar Pseudo-3D VPM is extended to a multimode flutter analysis. Finally, the structural response from the Pseudo-3D flutter and buffeting analyses is verified with the response, computed using the semi-analytical linear unsteady model in the time-domain. Meaningful merits of the turbulent Pseudo-3D VPM with respect to the linear unsteady model are the consideration of the 2D aerodynamic nonlinearity, nonlinear fluid memory, vortex shedding and local non-stationary turbulence effects in the aerodynamic forces. The good agreement of the responses for the two models in the 3D analyses demonstrates the applicability of the Pseudo-3D VPM for aeroelastic analyses of line-like structures under turbulent and laminar free-stream conditions.