Determination of the Fretting Regimes Under Stick-Slip Condition Using the Phase Difference Between Friction and Relative Displacement of Two Fretting Surfaces

Friction and wear characteristics between two steel surfaces under fretting condition are experimentally investigated. The fretting damage caused by low-amplitude oscillatory motions can be classified into three regimes of gross-slip, mixed-slip and partial-slip depending on the degree of stick-slip phenomenon. One of the most important characteristics of fretting wear is the transition behavior from gross-slip to mixed-slip. Several criteria have been introduced for a quantitative determination of the transition between mixed-slip and gross-slip. However, the transition criteria have some problems in determining the regimes because parameters are difficult to calculate and those are frequently depending on system. To introduce new transition criteria in this study, the phase difference between friction force and the relative displacement are used to determine the transition behavior and to predict the amount of fretting wear. The validation of phase difference is investigated by comparing the hysteresis graphs of friction force and the relative displacement with sine waves according to phase differences.