Is there more than one stickiness criterion?  

作　　者：Anle WANG Martin H.MüSER 

机构地区：[1]Department of Material Science and Engineering,Saarland University,Saarbrücken,66123,Germany [2]INM—Leibniz Institute for New Materials,Saarbrücken,66123,Germany

出　　处：《Friction》2023年第6期1027-1039,共13页摩擦（英文版）

摘　　要：Adhesion between an elastic body and a smooth,rigid substrate can lead to large tensile stresses between them.However,most macroscopic objects are microscopically rough,which strongly suppresses adhesion.A fierce debate has unfolded recently as to whether local or global parameters determine the crossover between small and large adhesion.Here,we report simulations revealing that the dependence of the pull-off force Fn on the surface energyγdoes not only have two regimes of high and low adhesion but up to four regimes.They are related to contacts,which at the moment of rupture consist of(i)the last individual Hertzian-shaped contact,in which is linear inγ,(ii)a last meso-scale,individual patches with super-linear scaling,(iii)many isolated contact patches with extremely strong scaling,and(iv)a dominating largest contact patch,for which the pull-off stress is no longer negligible compared to the maximum,microscopic pull-off stress.Regime(iii)can be seen as a transition domain.It is located near the point where the surface energy is half the elastic energy per unit area in conformal contact.A criterion for the transition between regimes(i)and(ii)appears difficult to grasp.

关 键 词：ADHESION pull-off force rough contact STICKINESS 

分 类 号：TH117[机械工程—机械设计及理论]