A nonlinear model of cable, able to twist, is formulated. For small sag-to-length ratios (e.g. 1/10) and technical parameter values proper to electrical transmission lines, the motion is ruled by the classical equations of the perfectly flexible cable, plus a further equation governing the twist evolution. A two degree-of-freedom system is successively obtained via a Galerkin procedure. The relevant nonlinear ODE’s are dealt with a Multiple Scale approach, under 2:1 internal resonance condition and no resonance conditions, in order to investigate Hopf bifurcations and post-critical behaviors. All the numerical results are compared with those furnished by the flexible model, and the influence of twist is discussed.
On the effect of twist angle on nonlinear galloping of suspended cables
LUONGO, Angelo;ZULLI, Daniele;
2009-01-01
Abstract
A nonlinear model of cable, able to twist, is formulated. For small sag-to-length ratios (e.g. 1/10) and technical parameter values proper to electrical transmission lines, the motion is ruled by the classical equations of the perfectly flexible cable, plus a further equation governing the twist evolution. A two degree-of-freedom system is successively obtained via a Galerkin procedure. The relevant nonlinear ODE’s are dealt with a Multiple Scale approach, under 2:1 internal resonance condition and no resonance conditions, in order to investigate Hopf bifurcations and post-critical behaviors. All the numerical results are compared with those furnished by the flexible model, and the influence of twist is discussed.Pubblicazioni consigliate
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