Effect of Surface Adhesion on the Rough Contact Response Near Complete Contact
Keywords:Hertz solution; Adhesive analysis; Rough surface modeling; Surface roughness; Surface energy
The adhesion phenomena between interfaces is widely investigated in engineering and scientific research. Due to the complexity of loading condition and surface topography, the traditional adhesive theory has many limitations. To better understand the adhesive properties of rough surfaces, we release the restrictions of JKR theory and propose a new adhesive model for single asperity. Initiated by this, a discrete rough surface contact model is presented, which extends the application scope of the traditional theory. First, we establish an elastic model by describing the gap between the interfaces accurately, so analytical solutions which are still valid for high contact pressure are proposed. Then, based on this, the exact adhesive solutions for different shapes of indenters are derived, which greatly improves the predicting accuracy of contact relationship and adhesion force. Finally, we use the results in the analysis of rough surface. The effect of both surface roughness and surface energy on the adhesive response of rough contact are studied in detail. The results show that adhesion is more easily to happen for smooth and geometrically continuous surfaces. The overall adhesion effect will be reduced in rough surface analysis with the increasing of surface roughness and the decreasing of surface energy. Our research sheds light on the understanding of the adhesion between solids and provides a theoretical guidance for the design of adhesion biomimetic materials and MEMS systems.