Abstract: One loading model of joint interface is described by means of the seamless connection of fractal geometry theory and traditional statistic contact mechanics theory, considering asperity transition process from elastic deformation, through elastoplastic deflection, to eventually plastic flow. The rough surface micro geometry topography is proposed adopting Weierstrass-Mandelbrot function with one stochastic phase. Numerical emulation curves display that normal total contact load micro protrusively increases with the increasing of real contact area and normal total contact force adds due to the increase of fractal roughness with the same real contact area; the percentage of real elastoplastic contact area to real contact area concavely decreases with increase in real contact area; the ratio of normal elastoplastic contact load to normal total contact load concavely diminishes as real contact area enhances and fractal roughness reduces; when fractal dimension ascends, normal total contact load undergoes two cyclic course that it first improves then shrinks later gains finally diminishes; the share of normal elastoplastic contact force to normal total contact force firstly lessens afterward aggrandizes with the increment of fractal dimension; the share of real elastoplastic contact area to real contact area above all decreases subsequently rises with the augment of fractal dimension; CEB model of overlooking elastoplastic deformation leads that its predicting normal contact force is larger than the elastoplastic model’s, besides, the relative error between CEB model’s normal contact force and the elastoplastic’s one lies within the range 4.798%-56.58%. Single loading model of joint interface will lay a theoretical foundation for the accurate solving of harsh surface elastoplastic contact.

Key words: limiting average pressure, circular frequency, contact area of the smallest spots, elastoplastic contact load, elastoplastic deformation, joint interface, stochastic phase