Session: VIB-02/MSNDC-10-03

Paper Number: 146367

146367 - Reducing Nonlinear Vortex-Induced Vibrations in Power Lines With Moving Nonlinear Absorbers 

Aeolian vibration is a significant factor contributing to the fatigue failure of power transmission lines. The mitigation of such vibrations in power lines has traditionally been achieved using Stockbridge dampers along the line spans, which are modeled as fixed vibration absorbers.  They largely depend on their resonant frequencies and placement on the cable. Therefore, given the stochastic nature of the wind, recent studies have explored the concept of dynamic/moving absorbers. Although the effectiveness of the moving absorber has been demonstrated in the literature to be superior to that of the fixed absorber, analyses have primarily been limited to linear cases and have not accounted for nonlinearity introduced by the moving absorber or the wind inflow on the powerline.  Aiming to fill this gap, this work combines the nonlinearities from the fluctuating lift force modeled as a van der Pol oscillator, with a  nonlinear moving absorber into a single model to investigate the effect of a nonlinear mobile damper relative to its linear counterpart. We observe that the system with a nonlinear moving absorber exhibits smaller amplitude oscillations when compared to its linear counterpart.  This finding underscores the superior mitigation characteristics of nonlinear vibration absorbers and suggests the potential for designing an optimal nonlinear moving vibration absorber.

Presenting Author: Ehab Basta Virginia Tech

Presenting Author Biography: Ehab Basta received his B.S. and M.S. in Mechanical Engineering from The American University of Sharjah in 2017 and 2019, respectively. His research focuses on Metastructures, Fluid-structure interaction, Nonlinear Dynamics, Perturbation Techniques, and Structural Vibration.

Authors:

Ehab Basta Virginia Tech
Sunit Gupta Virginia Tech
Oumar Barry Virginia Tech