Influence of friction force description on fretting wear considering stick-slip phenomenon

Various friction models were formulated to describe such a complex and naturally nonsmooth phenomenon. Generally, there are two categories of these models - static and dynamic. Static models describe friction phenomenon via friction characteristics governing the dependence of friction force on the relative velocity in the contact point. The basic Coulomb model is commonly implemented using its approximations by smooth functions (arctan, tanh) and a modified version of the model incorporating Stribeck effect is also widely used to describe different values of static and dynamic friction. The dynamic models are usually based on the bristle-analogy. In the contact surface, fictive deformable bristles are considered. From the mathematical point of view, dynamic models add one or more extra ordinary differential equation describing an average deflection of the bristles in the contact surface. These additional differential equations are solved together with the equations of motion. One of the basic dynamic models are Dahl or LuGre models, nevertheless there are even more sophisticated models such as elasto-plastic model, stick-slip model, Gonthier model etc. The choice of friction force plays important role during the simulations of various mechanical problems