Sustained rotation in a vibrated disk with asymmetric supports

TL;DR

This study investigates how a vibrated elastic disk supported asymmetrically can achieve sustained rotation, revealing that the rotation direction depends on excitation details and not just tilt, using simulations and analytical models.

Contribution

It introduces a novel analysis of rotational ratcheting in a vibrated disk with asymmetric supports, combining molecular dynamics simulations and simplified analytical models.

Findings

Rotation occurs under vibrational excitation and tilt.

Rotation direction depends on excitation details.

Analytical models explain the ratcheting mechanism.

Abstract

A single frictional elastic disk, supported against gravity by two others, rotates steadily when the supports are vibrated and the system is tilted with respect to gravity. Rotation is here studied using Molecular Dynamics Simulations, and a detailed analysis of the dynamics of the system is made. The origin of the observed rotational ratcheting is discussed by considering simplified situations analytically. This shows that the sense of rotation is not fixed by the tilt but depends on the details of the excitation as well.