基于接触分形理论的结合面切向接触刚度分形模型

以球体与平面接触时的切向接触刚度以及粗糙平面接触的分形理论为基础 ,基于 3个假设 ,即粗糙表面的微观形貌各向同性 ,粗糙表面上各微凸体之间的相互作用可以忽略不计 ,各微凸体所受的力与其接触面积的大小成正比 ,从理论上提出了具有尺度独立性的结合面切向接触刚度分形模型 ,并进行了定性的实验验证 ,说明了该模型的正确性。

A Fractal Model of Tangential Contact Stiffness of Joint Surfaces Based on the Contact Fractal Theory

The contact between joint surfaces is actually the contact between rough surfaces. According to the given hypotheses: (1) the micro profile of rough surfaces is isotropic, (2) the interaction between neighboring asperities on rough surfaces can be ignored, and (3) the force applied on each asperity on rough surfaces is directly proportional to its contact area, a fractal model of the tangential contact stiffness of joint surfaces in contact was built up based on the tangential contact stiffness between a sphere and a plane and the contact fractal theory of rough surfaces. The simulating results of this model show that the tangential contact stiffness of joint surfaces increases with the normal load on joint surfaces and the fractal dimension of joint surfaces, but not with the fractal roughness parameter of joint surfaces and the tangential load on joint surfaces. The results are qualitatively identical with the experiments, which indicates that this model is reasonable and is independent of scale.