Motion of a parametrically driven damped coplanar double pendulum

Abstract

We present the results of linear stability of a damped coplanar double pendulum and its non-linear motion, when the point of suspension is vibrated sinusoidally in the vertical direction with amplitude $a$ and frequency $\omega$. A double pendulum has two pairs of Floquet multipliers, which have been calculated for various driving parameters. We have considered the stability of a double pendulum when it is in any of its possible stationary states: (i) both pendulums are either vertically downward or upward and (ii) one pendulum is downward, and the other is upward. The damping is considered to be velocity-dependent, and the driving frequency is taken in a wide range. A double pendulum excited from its stable state shows both periodic and chaotic motion. The periodic motion about its pivot may be either oscillatory or rotational. The periodic swings of a driven double pendulum may be either harmonic or subharmonic for lower values of $a$. The limit cycles corresponding to the normal mode oscillations of a double pendulum of two equal masses are squeezed into a line in its configuration space. For unequal masses, the pendulum shows multi-period swings for smaller values of $a$ and damping, while chaotic swings or rotational motion at relatively higher values of $a$. The parametric driving may lead to stabilization of a partially or fully inverted double pendulum.

24 pages, 16 figures

References in corpus (2)

• Parametric Resonance of Optically Trapped Aerosols
• Rayleigh-Bénard magnetoconvection with temperature modulation

Cited by in corpus (1)

• Non-Floquet oscillations of a parametrically driven rigid planar pendulum