UNCERTAINTY QUANTIFICATION IN A TRANSMISSION LINE GUYED TOWER UNDER WIND LOAD

BRUNO RANGO; JORGE BALLABEN; RUBENS SAMPAIO; MARTA B. ROSALES

Florianopolis

Conferencia; ICVRAM-ISUMA UNCERTAINTIES 2018; 2018

ABCM-ASCE

Overhead transmission lines (TL) systems are widely used structures in the field of energy transmission. In general, the most conditioning factor in the design of the supporting towers is the wind load. In this sense, most of the standards and recommendations adopt a static approach. In particular, a static equivalent wind load is usually proposed. This model is supposed to account for both the mean and the turbulent component of the wind velocity. In the present paper, a different approach is explored. The dynamic structural response of a TL system subjected to a numerically simulated stochastic wind load field and self-weight, is evaluated. For this purpose, a three-dimensional finite element model of the (guyed?) tower and the conductors is implemented. In this scheme, the supporting tower is modelled as a linear equivalent beam-column, assuming the hypothesis of the Euler-Bernoulli beam theory. The second order effect caused by the combined action of the lateral wind load and the compressive axial load transmitted by the conductors is considered on the tower. The motion of the conductors, on the other side, are governed by a set of nonlinear equations which account for its extensibility and adopt the static deformed configuration under dead load as initial configuration. The stochastic wind load field is derived from its velocity field, which is divided in a mean and a turbulent (random) component. The random part of the wind velocity is obtained through its Power Spectral Density (PSD).