Investigation of nonlinear control of galloping with a linear beam with elastic boundary conditions

The aim of this study is nonlinear passive control of galloping oscillation on overhead transmission lines. The considered system is a linear beam subjected to harmonic and aerodynamic excitations which is coupled to a nonlinear absorber placed on an arbitrary position along the beam. Both extremities of the beam present rotationally and translationally elastic boundary conditions. After projection of spatio-temporal equations of the system on an arbitrary mode of the beam (the mode to be controlled), fast and slow system dynamics are traced which predict periodic or non periodic regimes. All analytical developments are compared with numerical results obtained from direct numerical integration of system equations and also from finite element modeling of the overall structure. Then, nonlinear passive control process of galloping instability by a non smooth nonlinear energy sink (NES) is investigated on a real case of galloping instability on a transmission line cable due to accretion of ice on it.