A detailed elastic analysis of the flat punch (Tack) test for pressure-sensitive adhesives

Detailed finite element calculations are carried out in order to study the mechanical response of a compliant layer sandwiched between a rigid cylindr ical Aat punch and a rigid substrate. Two cases of practical interest are c onsidered: one in which the layer is perfectly bonded to the punch and the substrate and one in which the interface between the punch and the layer is frictionless. The substrate is assumed to be perfectly bonded to the adhes ive layer in both cases. Analytic expressions are obtained for the stresses away from the edges, and the effect of lateral constraint is examined. The compliances of the loading systems for both cases are obtained numerically , and accurate analytic expressions are determined based on these numeric r esults. The nature of the stress fields near the contact edge are explored, and their connections with the energy release rate are determined. The rel evance of these calculations to two recent adhesion tests is discussed. (C) 2000 John Wiley & Sons, Inc.