自仿射接触点下的结合面静摩擦系数分形模型

Fractal Model of Static Friction Coefficient of Joint Surface Under Self-affine Contact Point

基于自仿射接触点的概念,对传统MB分形模型中结合面接触单个微凸体的函数表征不具有统计自仿射特性进行了修正,推导了结合面静摩擦系数的解析式,建立了结合面静摩擦系数分形模型,并与基于MB模型的结合面静摩擦系数分形模型进行了比较。通过仿真分析研究了分形参数对静摩擦系数的影响规律,结果表明结合面静摩擦系数随着无量纲法向接触载荷的增大而增大,随着无量纲特征尺度系数的增大而减小,随着分形维数的增大而增大。在与MB模型比较时有随着分形维数的增大,基于MB模型的结合面静摩擦系数分形模型对结合面静摩擦系数的预测结果比该研究模型偏小。

Based on the concept of self affine contact point,the function representation of the single micro convex contact point in the traditional MB fractal model is modified.The analytical formula of the static friction coefficient of the contact point is derived,compared with the fractal model of the static friction coefficient of the contact point based on the MB model,the fractal model of the static friction coefficient of the contact point is established.The influence of fractal parameters on the static friction coefficient is studied by simulation.The results show that the static friction coefficient increases with the dimensionless normal contact load and fractal dimension,and decreases with the dimensionless characteristic scale coefficient.Compared with MB model,the prediction results of the static friction coefficient of the interface based on MB model are smaller than those based on MB model.