AERODYNAMICS PHENOMENA IN TALL SLENDER BRIDGES

LES PHEONOMENS D'AEROELASTICITE DANS LES PONTS ELANCES

The aim of this study is to present in a simple way current theories on bridge aerodynamics. Two different phenomena are differentiated: wobble and resonance. Wobble is the instability resulting from the asymmetry between bending and torsion. The Theodorsen theory applicable to bonded wobble is briefly outlined and comments are made on the non-dimensional parameters contributing to the phenomenon. It is shown that this theory does not always reflect real conditions because of the unbonding of limit layers and that in each case experience must be taken into consideration. Resonance is a form of instability of a different nature caused by vortical escape (Benard Karmen vortices) in parts with defective cross-sections. With the theory, it is possible to predict critical wind velocities but not resonance amplitude. Mention is made of the usefulness of small-scale model experiments and of the basic principles of construction to follow in order to avoid aerodynamic instability or dangerous amplitudes. /TRRL/

  • Authors:
    • Bisch, P H
  • Publication Date: 1976-3

Language

  • French

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00188032
  • Record Type: Publication
  • Source Agency: Central Laboratory of Bridges & Highways, France
  • Files: ITRD, TRIS
  • Created Date: Mar 14 1979 12:00AM