Unloading contact mechanics analysis of elastic-plastic fractal surface

At present, there are many researches on the loading between contact surfaces, but it is also very important to predict the unloading process between rough surfaces. In this paper, based on the three-dimensional fractal loading model we built earlier and the unloading finite element results of the single asperity by Etsion et al., the unloading fractal prediction model between rough contact surfaces is established. The model takes into account the friction factor between surfaces, the three-dimensional fractal characteristics of rough surfaces and the elastic-plastic deformation mechanism of asperities. The model is compared with the unloading model based on the two-dimensional fractal curve established by Miao et al. and the finite element results. The results show that the unloading process between rough surfaces depends on the final loading state of the surface; the loading and unloading curves form a hysteresis loop, which represents the energy dissipation in a contact cycle; both the friction factor and fractal dimension of the contact surface have important effects on the unloading model.

Automated summary

This paper establishes an unloading fractal prediction model between rough contact surfaces based on a three-dimensional fractal loading model and previous research results, revealing that the unloading process depends on the final loading state of the surface, and both the friction factor and fractal dimension of the contact surface have significant effects on the unloading model.