EFFECTS OF HEIGHT DISTRIBUTION AND PSD ON THE ROUGH SURFACE ELASTOPLASTIC CONTACT BEHAVIOR

Accurate modeling and analysis of rough surface contact behavior represent a significant research topic in tribology, wear, and engineering problems. Due to the inherent complexity of rough surface contact problems, current studies primarily focused on conventional rough surfaces with Gaussian height distributions and fractal power spectral densities (PSD), and significant progress has been made in existing works. However, research on the contact behavior of non-Gaussian and non-fractal rough surfaces remains relatively limited. In this paper, a numerical method is employed to generate rough surfaces with specified characteristics of height distributions and PSD. Specifically, rough surfaces with three height distributions (Gaussian, Weibull, and Bimodal distributions) and two PSD functions (fractal and exponential functions) are generated to investigate the contact behavior on different rough surfaces. The frictionless elastoplastic contact problems of rough surfaces are solved using boundary integral and volume integral methods combined with the Fourier transform-accelerated numerical technique. The boundary integral method calculates elastic contact pressure, and the volume integral method can be applied to determine plastic strain and its effect on the displacement field. This numerical method can predict the contact results including real contact area, contact pressure, stress, elastic strain, and plastic strain. In addition, finite element simulations of rough surface contact are conducted to validate the accuracy and efficiency of the numerical approach. The proposed method further investigates how height distribution laws and power spectral density affect total contact area, spot area distribution patterns, and contact pressure distribution under elastoplastic deformation conditions. These results also indicate the influence of plastic deformation on the contact behavior. For the rough surface contact problems, both rough surface characteristics and elastoplastic constitutive model need to be considered in the modeling. These findings provide theoretical support for studying critical interfacial phenomena in electrical connectors, including friction, wear, heat transfer, and electrical conductivity at contact surfaces.