Linear instability mechanisms for coupled translational galloping

Linear instability mechanisms for coupled translational galloping

Instability Trends of Inertially Coupled Galloping, Part I: Initiation

The objective of this paper is to investigate the trends of the dynamic behavior of a single iced conductor. Attention is focused not only on the initiation of galloping but also on boundaries where a periodic plunge or torsional motion emerge. Trends with respect to the iced conductor’s eccentricity and its inertia to mass ratio are particularly stressed. They are shown to be complicated becau...

Instability Trends of Inertially Coupled Galloping, Part Ii: Periodic Vibrations

The non-resonant dynamic galloping of an iced, electrical transmission line is studied. Conditions and trends for the initiation of galloping have been given previously. Boundaries are presented here at which a periodic plunge or torsional motion loses stability and bifurcates into a quasi-periodic (mixed-mode) motion. Specific attention is given to the overall effects of an iced line’s eccentr...

Galloping instability of viscous shock waves

Motivated by physical and numerical observations of time oscillatory “galloping”, “spinning”, and “cellular” instabilities of detonation waves, we study Poincaré–Hopf bifurcation of traveling-wave solutions of viscous conservation laws. The main difficulty is the absence of a spectral gap between oscillatory modes and essential spectrum, preventing standard reduction to a finite-dimensional cen...

Nonlinear Instability of Coupled CNTs Conveying Viscous Fluid

In the present study, nonlinear vibration of coupled carbon nanotubes (CNTs) in presence of surface effect is investigated based on nonlocal Euler-Bernoulli beam (EBB) theory. CNTs are embedded in a visco-elastic medium and placed in the uniform longitudinal magnetic field. Using von Kármán geometric nonlinearity and Hamilton’s principle, the nonlinear higher order governing equations are deriv...