ten called the MYD transition) from DMT to JKR, as the We have generalized the Maugis model of the adhesive contact parameter m increases. The nature of this parameter, also of spheres (Maugis D., J. Colloid Interface Sci. 150, 243, 1992) to denoted l, with a slightly different definition, will be disarbitrary interactions in two different ways. On the one hand, if cussed below. Several papers have dealt with the MYD tranwe choose an arbitrary interaction potential between surfaces, we sition (7), often resorting to numerical solutions (8, 9).
obtain an exact formulation of the problem, which unfortunately
Unfortunately, these numerical solutions are computationrequires computationally demanding numerical solutions. On the ally demanding and may sometimes lead to serious errors, other hand, if we prescribe the stress distribution outside the conso that the MYD transition has often been considered a tact zone, we can build numerically efficient approximations which question best left to theoreticians.
completely describe the contact problem for a given monotonic attractive interaction with reasonable accuracy. These approxi-On the experimental side, therefore, when dealing with mate models retain the simplicity of the Maugis model and may the point contact of elastic solids, one usually uses the DMT therefore prove useful in data analysis. Our results show that the or the JKR model, according to the experimental conditions. nature of the interaction has a very moderate influence on the DMT has been shown to be valid when a large meniscus of solution, so that the Maugis model can be used to describe the condensed liquid is present (10), and JKR clearly applies contact of spheres with most physically acceptable interaction poto soft solids and large adhesion energy (4). However, it tentials, except when large accuracy is required. α§ 1998 Academic Press has recently been shown that, in some cases (11-13), the