Analysis of Adhesive Failure Using Generalised Fracture Mechanics

Abstract

Fracture mechanics analysis is of great value in adhesion studies since it defines adhesive failure parameters that are, in principle, independent of the test employed and thus characteristic of the adhesive bond itself⁽¹⁾. The chief drawback of fracture mechanics is that the fracture parameters obtained are purely empirical quantities and are not explicitly related to the surface or mechanical properties of the adhering phases.

Generalised fracture mechanics (GFM) seeks to overcome this problem by expressing the adhesive failure parameters in terms of the interfacial energy and the mechanical hysteresis properties of the bulk phases. This then permits the surface and bulk contributions to adhesive failure energy to be separated, allowing a more profound analysis of the fracture process and the way it is controlled by rate, temperature and other environmental factors. This will be illustrated by reference to specific studies on rubberlike and structural adhesives.