金属材料表面静摩擦学特性的预测研究-理论模型

摘要

The fractal geometric theory was modified.The improved fractal models for normal load,maximal static friction force and static friction coefficient were established using the improved fractal geometric theory.According to the intermediate variable of real contact area,the prediction model of static tribological performance of metallic material joint surface was given.The calculation and analysis indicate that the static friction coefficient slight-concavely increases as the normal load or material property parameter increases,while it slight-concavely decreases with the increasing of fractal roughness.When the fractal dimension is smaller,the static friction coefficient increases as the fractal dimension increases; however,when the fractal dimension becomes larger,the static friction coefficient decreases as the fractal dimension increases.The maximum static friction force is mostly linearly proportional to the normal load on a common logarithm reference frame.The fractal geometric theory can be taken in use under the condition of small normal load.%对分形几何理论进行了改进,在此基础上建立了法向载荷、最大静摩擦力、静摩擦系数的改进分形模型.通过中间自变量实际接触面积,构建了金属材料结合面静摩擦学特性的预测模型.计算和分析表明:静摩擦系数随着法向载荷或材料特性的增大而微凹弧式增大,但随着分形粗糙度的增加而微凹弧式减小；当分形维数较小时,静摩擦系数随着分形维数的增加而增加；但当分形维数较大时,静摩擦系数随着分形维数的增加而减小；在双常用对数坐标系统下,最大静摩擦力与法向载荷大多呈现出线性正比的关系；分形几何理论适用于法向载荷极小的情况.