Bifurcations in hybrid mechanical systems with discontinuity boundaries

The paper studies the dynamics of a stop-belt friction oscillator (SBO). The system consists of a visco-elastic oscillator which is dragged by a rough support moving with constant driving velocity and can collide with a rigid obstacle. The peculiarity of this system is that, in the phase space, it exhibits two different discontinuity boundaries. Nonsmooth responses are consequently observed with nonstandard attracting properties. The evolution of steady state limit sets as the position of the obstacle is varied is described. The nonsmoothness sets of the system and, in particular, the presence of discontinuity boundaries caused by friction and impacts, lead to nonstandard bifurcations which are studied here by means of analytical and numerical tools.