NONLINEAR ELASTIC ANALYSIS OF THE ADHESIVE STRENGTH BETWEEN RUBBER-LIKE MATERIALS AND RIGID SURFACES

A nonlinear elastic finite element analysis of the adhesive strength between rubber-like materials and rigid surfaces has been conducted based on fracture mechanics principles. The finite element model is an elastomer half sphere adhering to a rigid flat surface. An analytical solution for the system was first developed by Johnson, Kendall and Roberts (JKR) in 1971, which agrees well with experimental data for small contact area. The objective of this paper is to elucidate the relationship between the adhesive fracture energy, tensile loads and debonding process of the system when the contact area is large. A general analysis procedure for nonconforming adhesion-contact problem has been established in this study, which allows us to determine the adhesive fracture energy from measurements of the final pull-off force P-c or the zero-load contact radius ao. Our results agree well with JKR's prediction when the zero-load contact radius is less than 25% of tile radius of the sphere. However, as the contact radius increases, the debonding process deviates from JKR's prediction.