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Propagation of the Uncertainty in the Dynamic Behavior of OPGW Cables Under Stochastic Wind Load

Abstract:

In power transmission lines, conductors and guard wires are subjected to different types of mechanical vibrations, such as galloping, aeolian vibrations, and in the case of conductor bundles, sub-span oscillations. In this paper, a calibrated finite element model (FEM) is developed to evaluate the dynamic response due to aeolian vibrations of a single OPGW (Optical Ground Wire) cable with Stockbridge dampers. The model included the geometric, material, and damping characteristics of the OPGW cable and dampers, calibrated in previous work. The wind power input was simulated using a stochastic wind model based on Wiener processes, which allowed for a more realistic representation than deterministic models available in the literature. In addition, a Polynomial Chaos-Kriging (PCK) metamodel of the FEM model was constructed to reduce the computational cost of the model evaluation. The uncertainty of the wind load was propagated through the metamodel to obtain the distributions of the variables regarding the dynamic response, including the antinode and bending amplitudes, as a function of the Von Karman vortex shedding frequency. This was achieved using a Monte Carlo simulation approach, in which a large number of random simulations based on the wind model probability distribution were generated. The results were aggregated to obtain the distributions of the variables of interest. Field measurements were recorded with specific equipment to validate the simulation results. The results obtained in this study provide valuable insights into the dynamic behavior of cable-damper systems under aeolian vibrations, which are of great importance in their robust design.