结合面静态接触参数的统计模型研究

基于对粗糙表面形貌统计分析的基础上，综合考虑微凸体的完全弹性、弹-塑性和完全塑性三种变形机制，建立了结合面的接触面积、接触载荷及接触刚度的统计模型。该模型揭示了结合面接触参数与材料性能参数及粗糙表面形貌参数之间复杂的非线性关系。在不同的微凸体高度随机分布及塑性指数条件下，对接触参数进行预估和对比研究。结果表明，修正的指数分布对高斯分布有着较好的近似，而简单的指数分布与高斯分布之间的误差较大，且相差1至3个数量级；接触表面间距减小时，接触参数值均呈现增大的趋势；塑性指数增大时，接触载荷和接触刚度都随之增大，而接触面积的变化较小。

Statistical model for static contact parameters of joint surfaces

The paper presents a statistical model for static contact parameters of joint surfaces. The model is developed based on statistical analysis of surfaces topography, and the assumption that the transitions from fully elastic, through elastoplastic, to fully plastic deformation of an asperity are continuous. The nonlinear relationships between contact parameters and their influencing factors are simulated numerically under different distributions of asperity heights and plasticity indices. The results indicate that the modified exponential distribution is a good approximation to the Gaussian distribution. On the other hand, the estimates using the simple exponential distribution are 1 to 3 orders of magnitude larger than that of the Gaussian distribution. The contact parameters all increase as the mean separation between the two surfaces is decreased. In addition, the contact load and the contact stiffness increase with the plasticity index, but the changes of contact area are not significant.