Development of an improved Iwan model considering contact surface wear evolution and analysis of model contact characteristics

In this study, an improved Iwan model considering the evolution of contact surface wear was developed by defining a set of contact surface wear functions. The accuracy of the proposed model was subsequently validated through contact surface wear experiments. Based on this foundation, the contact characteristics of the model under various contact conditions were analyzed in detail. The results indicate that the increase of normal load causes the viscous range of the contact surface to increase gradually. In contrast, the increase of displacement amplitude leads to the change of the contact surface from local sliding to overall sliding. With the increase of wear cycles, the contact stiffness and friction coefficient of the worn contact surface also increase accordingly and gradually tend to be stable. In addition, under the overall sliding state, with the increase of the normal load and displacement amplitude, the dissipated energy of the contact surface also increases accordingly, and the wear phenomenon of the contact surface intensifies. This study can provide important theoretical guidance for studying contact surface wear mechanisms and life prediction.