Nonlinear spectral dynamic analysis of guyed towers. Part II: Manitoba towers case study

Abstract

Dynamic response of large complex space structures under wind loading is important in terms of performance and safety. Conventional method of wind loading calculation has been used successfully in codes to analyze large space structures. The method can be applied by approximating the air pressure, induced by wind, on the surfaces of structures. Although this replaces a wind loading test using complicated wind tunnel tests for any structural systems, the accuracy of the method, in the case of complex geometry guyed tower structures, is a matter of consideration. Hence, it is desirable to search for a procedure with more accuracy and reliability. In this respect, attention is paid to the advanced spectral element method and the computational fluid dynamics. Using the proposed formulation, a material and geometric nonlinear dynamic analyses have been performed to simulate post-buckling behaviours and also collapse modes for series of Manitoba Hydro's guyed towers under extreme wind loading conditions. Résumé : La réponse dynamique de grandes structures tridimensionnelles complexes sous des charges exercées par le vent est importante en termes de rendement et de sécurité. La méthode conventionnelle de calcul des charges dues au vent a été utilisée avec succès dans les codes pour analyser des grandes structures tridimensionnelles. La méthode peut être utilisée en appliquant une approximation de la pression d'air, induite par le vent, sur la surface des structures. Bien que cela remplace un essai des charges exercées par le vent qui utilise des essais compliqués en soufflerie pour tout système structural, il faut tenir compte de l'exactitude de la méthode dans le cas des tours haubanées, qui sont des structures géométriques complexes. Il est donc désirable de rechercher une procédure plus exacte et plus fiable. Concernant ces points, nous portons notre attention sur la méthode avancée des éléments spectraux et la dynamique des fluides numérique. En utilisant la formulation proposée, une analyse des matériaux et des analyses géométriques non linéaires ont été effectuées pour simuler le comportement post-flambement ainsi que les modes d'effondrement pour des séries de tours appartenant à Manitoba Hydro sous des conditions extrêmes de charges dues au vent.Mots clés : dynamique des fluides numérique, charge exercée par le vent, mode d'effondrement, analyse non linéaire, post-flambement.[Traduit par la Rédaction]

Dynamic behaviour of pre-stressed concrete transmission poles under synoptic wind loading

“…The supporting towers can be in the form of lattice steel towers or pole-type structures. Most of the previous studies which investigated the dynamic behavior of transmission line systems under wind loads focused on conductors and on lattice steel towers as the main supporting system (Momomura et al, 1997; Horr et al, 2004). Loredo-Souza and Davenport (1998) concluded that the aerodynamic damping of the conductors has a major effect on the dynamic behavior of transmission line structures.…”

Stability analysis of glass fibre polyamide composite transmission tower

“…wind loads and earthquakes. [5][6][7] Because of complex geometrical configurations, the dynamic characteristics of towers are nonlinear in character. Due to the power cable's vibration, dynamic loadings are generated in the transmission towers that lead to the failure of transmission tower.…”

Stability Analysis of Electric Transmission Line Tower Made with Composite Material Carbon Fiber Epoxy - An Innovative Approach

“…Most vibration studies on transmission line systems are conducted on transmission towers under wind loads [2][3]. Transmission towers are severely excited due to the effect of wind as well as earthquake.…”