Advanced dynamic methods for structural evaluation of TV towers

• Autorzy: Osterrieder P. , Beirow B.
• Języki publikacji: EN

Abstrakty

EN

On the background of the demand for an extended transmission capacity, the principles of static and dynamie behaviour of reinforced TV and telecommunication towers were investigated exemplarily at the Cottbus tower. The experimental part of the investigations is based on wind tunnel tests and permanent long-time measurements by a monitoring system acquiring data of wind situation and vibration velocity. The numerical part of the investigations was covered by conventional stochastic and deterministic methods for the calculation of the structural response due to along-wind and vortex shedding as well as by a new, hybrid and more close to reality numerical method based on neural networks. It could be shown that the serviceability of the Cottbus tower is actually not subjected to danger. The largest inclinations concerning permanent operation of transmission facilities result from along-wind and nonuniform temperature loadings over the shafts cross-section. As the most critical loading, with regard to questions of comfort and long-time behaviour, vortex shedding at the aerial antenna could be identified. Moreover, considerable reserves with a view to an extension of transmission facilities could be proved. Nevertheless, it was shown that these extensions cause a considerable increase in along-wind loadings, which could effect a critical structural response in case of towers having a lower stiffness. In order to avoid any risk from the outset, a strategy for planning operational changes was proposed on principle.

Słowa kluczowe

EN

reinforced telecommunication tower; structural dynamic response; serviceability; wind tunnel test; neural networks; operational changes; fatigue life

• Wydawca: Oficyna Wydawnicza Politechniki Opolskiej
• Czasopismo: Zeszyty Naukowe. Budownictwo / Politechnika Opolska
• Rocznik: 2003
• Tom: z. 47
• Strony: 103--115
• Opis fizyczny: Bibliogr. 8 poz., rys., schem.

Twórcy

autor

Osterrieder P.

• Structural Analysis, BTU Cottbus

autor

Beirow B.

• Structural Analysis, BTU Cottbus

Bibliografia

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• [2] OSTERR1EDER P. & BEIROW B. (1999). Monitoring of Transmission Towers. Proc. of the 4th European Conference on Structural Dynamics EURODYN ‘99 /Prague/CZ, Balkema, Rotterdam, Netherlands.
• [3] BEIROW B. (2000). Experimentelle und theoretische Untersuchungen des dynamischen Veraltens von Fernmeldeturmen, PhD-Thesis, Cottbus, Germany.
• [4] CLORMANN U. H. & SEEGER T. (1986). Rainflow-HCM. Ein Zahlverfahrcn Fur Betriebsfcstigkeitsnachweise auf werkstoffmechanischer Grundlage. Stahlbau 55, Heft 3, S. 65-71, Ernst & Sohn Vcrlag, Berlin.
• [5] ISO 2631, Part 2 (1989). Evaluation of Humań Exposure to Whole-Body Yibration: Continuous and Shock-induced Yibration in Buildings (1 to 80 Hz). International Standards Organization, Geneva, Italy.
• [6] ENV 1991-2-4 (1995). Eurocode 1: Basis of Design and Actions on Structures. Part 2.4: Wind Actions CEN/TC 250/SC1.
• [7] SCHROTH G. & OSTERRIEDER P. & BEIROW B. (1997). Control and Inspection of Transmission Towers Using Dynamie Methods. Proc. XLIII Konferencja Naukowa Problemy Naukowo - Badawcze Budownictwa, Tom III, Krynica, Poland.
• [8] UAIBACH E. (1989). Belriebsfestigkeit - Yerfahren und Daten zur Bauteilberechnung. VDI-Verlag, Dusseldorf, Germany.