RT Journal Article
SR Electronic
T1 The rolling suitcase instability: a coupling between translation and rotation
JF Proceedings of the Royal Society A: Mathematical, Physical and Engineering Science
FD The Royal Society
DO 10.1098/rspa.2017.0076
VO 473
IS 2202
A1 Facchini, G.
A1 Sekimoto, K.
A1 du Pont, S. Courrech
YR 2017
UL http://rspa.royalsocietypublishing.org/content/473/2202/20170076.abstract
AB A two-wheel suitcase or trolley can exhibit undamped rocking oscillations from one wheel to the other when pulled fast enough. We study this instability both experimentallyâ€”with a toy model of a suitcase rolling on a treadmillâ€”and theoretically. The suitcase oscillates only if a finite perturbation is applied. This is because intrinsic dissipation occurs when the supporting wheel switches. When unstable, the suitcase either increasingly rocks until overturning or reaches a stable limit cycle. The friction force at the rolling wheels constrains wheels to roll without slipping. This constraint imposes a coupling between the translational motion and the three-dimensional rotational motion of the suitcase that drives the rocking instability. The same behaviours are observed in the experiments and in the simulations. The asymptotic scaling laws we observe in the simulations are explained by means of a simplified model where the coupling force is explicit.