doi:10.3850/978-981-08-7619-7_P060

ABSTRACT

In this paper the response of a nonlinear tower-line system excited by stochastic wind loading is considered. Interest in this work has emerged due to the importance of power transmission and its complex steel lattice system connecting wind-sensitive lines. An approximate 3-degree-of freedom model for a typical transmission tower-line system is established. It accounts for the nonlinear nature of the tower stiffness and the dynamic characteristics of the transmission lines and exhibits softening nonlinearity characteristics. Given the power spectrum of the wind load, the method of statistical linearization is used to determine iteratively the response statistics of the tower-line system. Interestingly, beyond a certain mean wind velocity, the iterative procedure of the statistical linearization ceases to converge. This is an indication of a precarious tower-transmission line operation. With regards to this, the developed procedure can be used as an auxiliary tool in the transmission tower design phase. Further, the system response probability density function is derived to predict the reliability of the transmission tower; it is found in a good agreement with data obtained by an appropriate Monte Carlo study. Hopefully, this idealized system model in conjunction with the statistical linearization technique, will be readily applied in the dynamic response analysis and reliability estimation of wind-excited transmission towers at a high efficiency level.

Keywords: Tower-line, Electric Power transmission, Wind, Softening Duffing System, Statistical linearization, Reliability.

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