Stick-Slip Transition Appearing in A Disk-Ball System

Abstract

AbstractOur experiments relating a disk-ball system show that the sequential motion of a resting disk impacted by a pendulum-based ball can exhibit striking characteristics of reflecting the effects from friction. Under the impact action for trigging a planar motion, the disk first slides on a fixed surface, then sticks at the contact point with a rotation motion, after that slip motion is resumed until a surface impact occurs. The motion of the disk is measured accurately by using two laser-Doppler vibrometers capturing the instantaneous velocities of two points intersected by two horizontal laser lines shotting on the disk surface. The physical parameters relating the coefficient of restitution, and the ones of dynamic and static coefficients of friction are identified from experiments, thus no fitting parameters are adopted in simulations. Comprehensive numerical and experimental investigations relating the process of initially multiple impacts and the subsequent motion of the disk are carried out by setting the impacting position spanning the symmetry axis of the disk surface. Good agreements are found in the comparisons between numerical results and experimental observation.