Finite element modelling of transmission line galloping

• Published in: Computers & structures Vol. 57; no. 3; pp. 407 - 420
• Main Authors: Desai, Y.M., Yu, P., Popplewell, N., Shah, A.H.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.11.1995; Elsevier Science
• Subjects: Applied sciences; Electrical engineering. Electrical power engineering; Electrical power engineering; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Physics; Power networks and lines; Solid mechanics; Structural and continuum mechanics; Theory. Simulation; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Vibrations and mechanical waves; Finite element method; Power transmission lines; Transmission line; Non linear damping; Wind effects; Numerical methods; Dynamic stability; Aeroelasticity; Galloping
• ISSN: 0045-7949; 1879-2243
• DOI: 10.1016/0045-7949(94)00630-L

A computationally efficient, finite element idealization is presented to analyse galloping, which is characterized by large amplitude vibrations of iced, multi-span, electrical transmission lines. A three-node, isoparametric cable element having three translational and a torsional degree-of-freedom at each node is developed to model a conductor. Support insulator strings and remote conductor spans are represented by linear static springs. A transmission line's interactions with a support tower are modelled through the tower's equivalent stiffness at the conductor's suspension point. An expedient time marching scheme is developed to obtain the envelope of galloping. The scheme can be utilized to integrate dynamic equilibrium equations involving not only geometric and material nonlinearities but also nonlinear damping. Time integration is performed in the sub-space to minimize computational effort. The finite element model has been employed to successfully simulate field galloping records. It is shown that it is necessary to consider a multi rather than a single span for a conservative estimate of the galloping amplitudes to enable sufficient clearances to be designed between adjacent conductors.