Abstract: Based on contact fractal theory, modified MB fractal model, and considering the mechanism of energy dissipation and the elastoplastic deformation regime(not only fully elastic or plastic regime or plastic and elastic regime) of plane joint interfaces, an elastoplastic fractal model, considering the influence of domain extension factor on micro-contact size distribution, is proposed. Numerical simulations show the influence of elastoplastic deformation regime on dimensionless tangential damping dissipation is not obvious when fractal dimension D value between 1.1 and 1.4 compared with only considering elastic and plastic deformation regime, while if is found that dimensionless tangential damping dissipation considering elastoplastic deformation regime less than that of only considering elastic and plastic deformation regime when fractal dimension D value between 1.4 and 1.9. There is a concave nonlinear relation between dimensionless tangential damping dissipation and dimensionless total normal load, and the influence of fractal dimension D on dimensionless tangential damping dissipation is different when D=1.1-1.4,D=1.4-1.6, D=1.6-1.8, D=1.8-1.9, respectively. Besides, dimensionless tangential damping dissipation increases with the increment of fractal roughness, plastic index, and the ratio of total normal load to total tangential load.

Key words: Elastoplastic, Energy dissipation, Fractal model, Machine joint interfaces, Tangential contact damping