Summary
This work examines the instability mechanism of a two-degree-of-freedom mass-on-moving belt system. The frictional interaction between the mass and the belt is governed by the Amontons-Coulomb law and a nonlinear normal contact force represented by the Hertz-Damp model. Nonlinear numerical analysis and a linearised stability analysis are conducted for both the unforced and the forced system. It is shown that, for certain model parameters, the excited system becomes unstable. The influence of damping on the stability is assessed as well. This study also demonstrates how the presence of instability affects vibration-induced friction modulation, leading to a reduced but largely scattered average friction force for specific belt velocities.
