基于分形几何的表面微观形貌模拟及粘着弹性接触计算研究

基于Ausloos和Berman提出的推广的W-M函数对具有分形特征的粗糙表面进行仿真模拟,分析了函数中与尺度无关的特征参数对表面微观形貌的物理意义。同时,基于Yan和Maugis的理论研究,用模拟的分形表面建立了考虑表面效应的弹性接触模型,通过数值方法对整个过程进行迭代求解,得到了两接触面在不同的接触条件下各个接触斑点上的载荷分布和真实接触面积以及接触斑点的数量和尺寸。由于真实接触面积的尺寸敏感地反应表面微观几何形貌的变化,因此该方法为研究粘着机制和减小微尺度粘着效应提供了思路。

Simulation of Surface Micro-topography Based on Fractal Geometry and Calculating of Adhesive Elastic Contact

Rough surfaces which have fractal character were simulated based on generalized W-M function presented by Ausloos and Berman, and the physical significance of the scale-independent fractal parameters on the surface micro-topography was elucidated. Taking account of surface effect in contact interface, elastic contact model for simulated fractal surfaces was proposed based on the solution provided by Yan and Maugis. A numerical iteration scheme was used to solve for load of asperities, real area of contact for each asperity, total number of contact spots and size of contact spots with given contact conditions. The scale of real contact area is sensitive to the change of surface micro-topography, so the presented method provides a clew for research of adhesive mechanism and diminishing microscale adhesive effect.