A wind tunnel analysis of flutter vibrations of a U-beam

0429315 - ÚTAM 2015 RIV PT eng C - Konferenční příspěvek (zahraniční konf.)
Strecha, J. - Kuznetsov, Sergeii - Král, Radomil - Pospíšil, Stanislav - Spitzy, L. - Steinrück, H.
A wind tunnel analysis of flutter vibrations of a U-beam.
Proceedings of the 9th International Conference on Structural Dynamics. EURODYN 2014. Porto: European Association for Structural Dynamics (EASD), 2014 - (Cunha, A.; Caetano, E.; Ribeiro, P.; Müller, G.), s. 3113-3120. ISBN 978-972-752-165-4. ISSN 2311-9020.
[International Conference on Structural Dynamics. EURODYN 2014 /9./. Porto (PT), 30.06.2014-02.07.2014]
Grant CEP: GA MŠMT(CZ) ED1.1.00/02.0060; GA ČR(CZ) GC13-34405J
Institucionální podpora: RVO:68378297
Klíčová slova: fluid structure interaction * bridge deck aerodynamics * vortex induced vibrations * self excited vibration
Kód oboru RIV: JM - Inženýrské stavitelství
http://paginas.fe.up.pt/~eurodyn2014/CD/papers/435_MS20_ABS_1318.pdf

Motivated by assessing the aeroelastic stability of a conveyor solution, the aeroelastic stability of a U-beam with an aspect ratio (width B over frontal height H) of B/H = 4.62 is investigated. Wind-tunnel experiments involving a special test stand for sectional models and complementary CFD simulations were carried out. We find that the U-beam can perform self-excited two-degree of freedom (flutter) vibrations. This is also reflected in the simulation results. Vortex-induced vibrations were observed experimentally, but the amplitudes were small in respect to the frontal height. Numerically, it was found that there exist two different patterns of the flow around the U-profile: One pattern that is very similar to the flow around a rectangular prism ( “R-flow” pattern) and another pattern were the flow “reaches” into the pocket of the profile (“U-flow” pattern). The amplitude of vortex induced vibrations depends strongly on the flow pattern. When the R-flow pattern is realized, the amplitudes were again small and of the same order of magnitude as in the experiments. When the U-flow pattern is realized, much greater vibration amplitudes were observed in the simulations. Up to now, this could not be observed in the wind tunnel experiments. However, for self-excited vibrations at higher reduced velocities it appears that the U-flow pattern cannot be sustained: After an initial phase the flow pattern changes to the R-flow pattern.
Trvalý link: http://hdl.handle.net/11104/0234440