Nonlinear vibrations in a covered roll system with viscoelastic contact

A theoretical analysis on the contact vibration problem of a nip rolling system composed with two paper machine rolls is presented. It is modelled at the contact region by a two-degree-of-freedom (DOF) mass-spring-damper system. The rolling contact force in a case of viscoelastic polymer covered roll is formulated by integration of the contact stress. Regenerative chatter effects to the stability of the vibrations are considered. The perturbation technique is applied through the multi-scale method to calculate the nonlinear normal form of the governing equations to determine the stability behavior of the system. The numerical results in time domain are consistent with the bifurcation diagrams.