Stochastic synchronization of rotating parametric pendulums

In this paper synchronization of two pendulums mounted on a mutual elastic single degree-of-freedom base is examined. The response of the pendulums is considered when their base is externally excited by a random phase sinusoidal force, thus leading to stochastic parametric excitation of the pendulums. The target is for the pendulums to establish and preserve rotary response since this study is motivated by a recently proposed ocean wave energy extraction concept where the heaving motion of waves excites a pendulum’s hinge point. Since the wave bobbing motion is random the system’s excitation is modelled as a narrow-band stochastic process. Mounting two pendulums on the same elastic base creates a coupling between them through their interaction with the base, providing a path for energy exchange between them. The dynamic response of the pendulums is numerically investigated with respect to establishment of rotations as well as identification of synchronization with the pendulums characteristics spanning along non-identical parameters.     

On the dynamics of a nonlinear energy harvester with multiple resonant zones

Nonlinear Dynamics - The dynamics of a nonlinear vibration energy harvester for rotating systems is investigated analytically through harmonic balance, as well as by numerical analysis. The...     

Design and validation of a nonlinear vibration absorber to attenuate torsional oscillations of propulsion systems

Nonlinear Dynamics - Recent developments in propulsion systems to improve energy efficiency and reduce hazardous emissions often lead to severe torsional oscillations and aggravated noise....     

Stability of an autoparametric pendulum system with impacts

This paper considers a small oscillatory motion of a pendulum suspended on a single-degree-of-freedom system subjected to a narrow band excitation and impacts due to a barrier located at a certain distance from the system?s equilibrium position. The influence of a impacting motion of the single-degree-of-freedom system onto the instability boundaries of the pendulum is investigated. It is demonstrated that the impacting motion significantly changes the shape of the instability domain compared to the traditional one inherent to the Mathieu equation.