Insight Into the Drift Motion of a Bouncing Asymmetric Dimer

The drift motion of an asymmetric dimer bouncing on a harmonically vibrating plate is addressed in this paper. The direction of this motion is determined by the behavior of the dimer during a double impact. Namely, if the system parameters allow a sticking impact as a generic behavior, the dimer drifts in one direction, whereas if all impacts end in a reverse slip, the dimer drifts in the opposite direction. By this mechanism, the bifurcation coefficients dominating the drift direction are obtained and discussed. But strictly speaking, the drift direction does not change unless the reverse slipping displacement after a double impact is big enough. Thus, numerical simulations are carried out to find a more accurate threshold and check the rationality of theoretical results.