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Talks and Poster Presentations (without Proceedings-Entry):

F. Ziegler:
"The tuned liquid column damper as the cost-effective alternative of the mechanical damper within vibration prone civil engineering structures";
Keynote Lecture: ICSV13 Thirteenth International Congress on Sound and Vibration, Wien (invited); 2006-07-02 - 2006-07-06.



English abstract:
Modern architecture, limited space in urban area and new developments in building construction techniques have caused an increased need to construct flexible and tall structures. However, many of those structures are vibration prone and even minor dynamic loads like regularly occurring wind gusts may cause occupant discomfort, especially in the upper floors of high-rise buildings. On the other hand, earthquakes and strong winds often cause structural damage or even failure and thus an increased awareness about the vulnerability of modern structures became public. These include large dams and all kinds of light bridges from footbridges to long-span bridges with the need of increased effective structural damping. In the course of the cantilever method of bridge construction, critical states are encountered in windy situations. Consequently, there is a higher demand to protect the structures from all kinds of dynamic loads. Damping in the low frequency range of such vibration prone C.E. structures requires a concentration of energy for its efficient dissipation. The classical tuned mechanical damper (TMD) requires high investments and maintenance fees. In all respects, the tuned liquid column damper (TLCD) is superior, and it is analyzed and, in a first step modally tuned, using a recently established geometrical analogy to the TMD. When sealed, choosing the right gas pressure in chambers above the liquid surface extends the frequency range of application from close-to-zero to about five Hertz. The slightly over-linear gas-spring effect in combination with the averaged turbulent damping of the (relative) fluid flow (verified experimentally), protect the TLCD from overload by detuning. Fine-tuning in state space improves the performance even further. Fuzzy stiffness can be accounted for in the design stage. The result is a robust control in the frequency window around a resonance of the main structure with its effective structural damping dramatically increased.

Created from the Publication Database of the Vienna University of Technology.