A three-dimensional fractal contact model of rough surfaces considering strain hardening

Strain hardening has a significant influence on the contact behavior of rough surfaces. In this study, an asperity contact load model accounting for strain hardening is built with continuous and monotonic properties at the critical point. Furthermore, the asperity contact model is extended to a whole rough surface by integrating asperity interactions and a three-dimensional fractal contact model of rough surfaces that considers strain hardening is established. The contact characteristic of the proposed model is evaluated and compared to those of existing fractal contact models and experimental results. Then, the influences of the real contact area, strain hardening exponent, fractal surface parameters, and material properties on the contact load are investigated. The results of the proposed model are more consistent than those of the existing fractal models with respect to experimental data. The contact load decreases as the strain hardening exponent increases. The contact load depends sensitively on the fractal dimension and exhibits nonmonotonic characteristics. This model increases the depth of insights needed for forecasting of the contact characteristics of engineering structures.