STICK-SLIP MOTION OF A RESIN-STEEL CONTACT AT LOW SPEEDS

Low speed sliding bearings are widely used in many industrial engineering fields. Friction induced vibration sometimes occurs, which decreases the performance and the life of machines besides introducing heavy noise. It is still quite difficult however, to predict the occurrence of the frictional vibration due to the nonlinearity of the system. This paper tries to address the occurrence of stick-slip motion by means of experiments and simulations. With a specially designed test device, extensive tests were carried out on face-to-face contact specimens of a resin material (Polyamide 6) that rotates against steel specimens, to understand the occurrence of stick-slip motion. Math models have been employed to describe the discontinuous transition between the static and the kinetic friction coefficient of the rubbing pairs. Based on the transition law, two contact models were employed to describe the dynamic interaction between the resin and the steel specimens. A special subroutine was then implemented in Adams by C-language. Simulations were conducted for the influence of contact pressure and relative speed on the occurrence of the stick-slip motion. Comparisons show the applicability and accuracy of the models.