The effect of frequency of vibration and humidity on the stick–slip amplitude

This work examines the variation of stick–slip amplitude with the variation of frequency of vibration and relative humidity on a mild steel disc. A pin-on-disc machine, developed by the authors, capable of vibrating the disc at different frequency is used for the experiments. During the experiments, normal load, speed, relative humidity and frequency of vibration were varied. The results reveal that, depending on the conditions, a different stick–slip behavior can arise in the same system. It is found that the rate of reduction of stick–slip amplitude has a particular relationship with the frequency of vibration and the relative humidity. It is also observed that the transition from irregular to regular stick–slip behavior is load dependent, while the transition from irregular to smooth sliding is load independent.