Cohesive failure of adhesive joints

Abstract

Present interest in adhesives is intense, since in many ways they provide the ideal means of joining components, especially those assembled by robot techniques. In this paper, it is shown how the measured strength of an adhesive joint reflects the interaction between the properties of substrate, adhesive, and the interface between them. Work is discussed which shows how the peel strengths of model systems have been varied by both altering the interfacial bonding and changing the mechanical properties of the adhesive. Appropriate changes to surface topography as well as the introduction into the adhesive of second ‘phases’, which may be hard or soft, or even bubbles, can produce significant joint toughening in a range of adhesive joints. For the future, improved prediction of joint service properties from design data is to be expected. This will come from the further application to adhesive joints of fracture mechanics, time–temperature superposition techniques, slipline field theory, and finite element analysis.

MST/723