Micro sliding friction model considering periodic variation stress distribution of contact surface and experimental verification

Abstract

Micro sliding phenomenon widely exists in the operation process of mechanical systems, and the micro sliding friction mechanism is always a research hotspot. In this work, based on the total reflection method, a measuring device for interface contact behavior under two-dimensional (2D) vibration is built. The stress distribution is characterized by the light intensity distribution of the contact image, and the interface contact behavior in the 2D vibration process is studied. It is found that the vibration angle of the normal direction of the contact surface and its fluctuation affect the interface friction coefficient, the tangential stiffness, and the fluctuation amplitude of the stress distribution. Then they will affect the change of friction state and energy dissipation in the process of micro sliding. Further, an improved micro sliding friction model is proposed based on the experimental analysis, with the nonlinear change of contact parameters caused by the normal contact stress distribution fluctuation taken into account. This model considers the interface tangential stiffness fluctuation, friction coefficient hysteresis, and stress distribution fluctuation, whose simulation results are consistent well with the experimental results. It is found that considering the nonlinear effect of a certain contact parameter alone may bring a greater error to the prediction of friction behavior. Only by integrating multiple contact parameters can the accuracy of friction prediction is improved.