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Finite Element Modelling of Electrical Overhead Line Cables under Turbulent Wind Load

DOI: 10.1155/2014/421587

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Abstract:

This paper presents a finite element model of an overhead transmission line using so called cable elements which allow reproducing the cable’s nonlinear characteristics accurately employing only a few elements. Aerodynamic damping is considered in the equation of motion by taking into account the relative velocity between the flow of the wind and the moving structure. The wind flow itself is simulated by wave superposition making necessary assumptions on the lateral correlation between the wind velocities along the cable length. As result from the simulation, the following conclusions can be drawn. The first natural frequency of generally used wide spanning cables lies well below 1?Hz where also most of the energy content of the wind excitation is to be expected. Aerodynamic damping is significant for the moving cables holding very low structural damping which leads to a suppression of resonant amplification. This is particularly of interest regarding the support reaction which is dominated by the mean value and the so called background response. The latter is mostly influenced by the randomness of the wind flow, especially lateral to the main wind direction. 1. Introduction Spanning over a few hundred meters, being light, and having slender structures, the wind acting on the cables contributes significantly to the overall loading of the suspension towers [1]. Both modelling of the cables and simulation of the acting wind field have to be undertaken with care to account for the particularities of such a horizontally expanded structure. Such specific features in modelling involve the nonlinear structure, the nonlinear equation of motion, and an adequate simulation of the acting wind. The last is more often described in its nature along and vertically to the main wind direction than in its lateral character which is more important for horizontally expanded structures. Many works have already dealt with this issue with different approaches, aims, and results. We start with early works [2] which gave a preliminary insight into the structural characteristics of overhead transmission line cables more than into the details of the wind excitation. Those works were soon followed by simulations [3] highlighting the importance of incorporating nonlinear effects and aerodynamic damping in regard to supporting reaction of suspended cables but without emphasizing the importance of the assumptions of the acting wind. Even in recent work, that aspect is not always included [4, 5]. Later studies on wind tunnel models [6] stress again the need of detailed analysis when

References

[1]  R. Kadaba, “Response of electrical transmission line conductors to extreme wind using field data,” in Civil Engineering, p. 142, Texas Tech University, 1988.
[2]  C. Manuzio, “Wind effects on suspended cables,” in Wind Effects on Buildings and Structures, pp. 337–370, University of Toronto Press, Ottawa, Canada, 1968.
[3]  M. J. Matheson and J. D. Holmes, “Simulation of the dynamic response of transmission lines in strong winds,” Engineering Structures, vol. 3, no. 2, pp. 105–110, 1981.
[4]  A. Y. Shehata, A. A. El Damatty, and E. Savory, “Finite element modeling of transmission line under downburst wind loading,” Finite Elements in Analysis and Design, vol. 42, no. 1, pp. 71–89, 2005.
[5]  F. Cluni, V. Gusella, and F. Ubertini, “A parametric investigation of wind-induced cable fatigue,” Engineering Structures, vol. 29, no. 11, pp. 3094–3105, 2007.
[6]  A. M. Loredo-Souza and A. G. Davenport, “The effects of high winds on transmission lines,” Journal of Wind Engineering and Industrial Aerodynamics, vol. 74–76, pp. 987–994, 1998.
[7]  V. Gattulli, L. Martinelli, F. Perotti, and F. Vestroni, “Dynamics of suspended cables under turbulence loading: reduced models of wind field and mechanical system,” Journal of Wind Engineering and Industrial Aerodynamics, vol. 95, no. 3, pp. 183–207, 2007.
[8]  R. Karoumi, “Some modeling aspects in the nonlinear finite element analysis of cable supported bridges,” Computers and Structures, vol. 71, no. 4, pp. 397–412, 1999.
[9]  B. Yan, X. Lin, W. Luo, Z. Chen, and Z. Liu, “Numerical study on dynamic swing of suspension insulator string in overhead transmission line under wind load,” IEEE Transactions on Power Delivery, vol. 25, no. 1, pp. 248–259, 2010.
[10]  H. B. Jayaraman and W. C. Knudson, “A curved element for the analysis of cable structures,” Computers and Structures, vol. 14, no. 3-4, pp. 325–333, 1981.
[11]  H.-T. Thai and S.-E. Kim, “Nonlinear static and dynamic analysis of cable structures,” Finite Elements in Analysis and Design, vol. 47, no. 3, pp. 237–246, 2011.
[12]  K. J. Bathe, Finite Element Procedures in Engineering Analysis, 1982.
[13]  H. M. Irvine and T. K. Caughey, “The linear theory of free vibrations of a suspended cable,” Proceedings of the Royal Society of London A, vol. 341, no. 1626, pp. 299–315, 1974.
[14]  L. Carassale and G. Piccardo, “Non-linear discrete models for the stochastic analysis of cables in turbulent wind,” International Journal of Non-Linear Mechanics, vol. 45, no. 3, pp. 219–231, 2010.
[15]  IEC, Design Criteria of Overhead Transmission Lines, International Electrotechnical Commission, Geneva, Switzerland, 2003.
[16]  M. J. Paluch, T. T. O. Cappellari, and J. D. Riera, “Experimental and numerical assessment of EPS wind action on long span transmission line conductors,” Journal of Wind Engineering and Industrial Aerodynamics, vol. 95, no. 7, pp. 473–492, 2007.
[17]  M. Shinozuka and C.-M. Jan, “Digital simulation of random processes and its applications,” Journal of Sound and Vibration, vol. 25, no. 1, pp. 111–128, 1972.
[18]  EN, Eurocode Actions on Structures—General Actions, in Part 1–4, vol. 1, Wind Actions, 2010.
[19]  G. Solari, “Turbulence Modeling for Gust Loading,” Journal of Structural Engineering, vol. 113, no. 7, pp. 1550–1569, 1987.
[20]  G. Solari, “Gust buffeting. I: peak wind velocity and equivalent pressure,” Journal of Structural Engineering, vol. 119, no. 2, pp. 365–382, 1993.
[21]  V. Deno?l, “Accounting for coherence in wind forces in finite element models,” in Proceedings of the European Conference on Structural Dynamics (EURODYN '05), pp. 2219–2224, Millpress, 2005.
[22]  G. Solari and G. Piccardo, “Probabilistic 3-D turbulence modeling for gust buffeting of structures,” Probabilistic Engineering Mechanics, vol. 16, no. 1, pp. 73–86, 2001.
[23]  A. G. Davenport, “Gust response factors for transmission line loading,” in Proceedings of the 5th International Conference on Wind Engineering, Pergamon Press, Fort Collins, 1979.
[24]  D. Stengel and M. Mehdianpour, “Wind measurements along a high-voltage overhead transmission line in Northern Germany,” in Proceedings of the 4th International Conference on Integrity, Reliability & Failure, INEGI-Instituto de Engenharia Mecanica e Gestao Industrial, Funchal, Portugal, 2013.
[25]  A. G. Davenport, “How can we simplify and generalize wind loads?” Journal of Wind Engineering and Industrial Aerodynamics, vol. 54-55, pp. 657–669, 1995.
[26]  A. Preumont, “On the peak factor of stationary Gaussian processes,” Journal of Sound and Vibration, vol. 100, no. 1, pp. 15–34, 1985.
[27]  C. Floris and L. De Iseppi, “The peak factor for gust loading: a review and some new proposals,” Meccanica, vol. 33, no. 3, pp. 319–330, 1998.

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