An original epoxy-stamp on glass-disc specimen exhibiting stable debonding for identifying adhesive properties between glass and epoxy

In Contact Mechanics and Tribology, adhesion is the conservative reversible normal relation (contiguity) and attractive interaction (tension) at the interface between two materials in contact. ”Deadhesion ” or rather decohesion, is the loss of adhesion. In Fracture Mechanics and Rheology, debonding is usually interpreted as a crack propagating along the material pair interface at the microscale and as damage at the macroscale. This study is motivated by the fibre-matrix debonding which occurs in glass fibre reinforced epoxy matrix composites and decreases their strength. In this note, we focus our attention on the identification of the adhesive properties between glass and epoxy. The basic adhesive property, entering a normal adhesion-decohesion law relating the normal tensile stress pn to the normal gap gn at an interface, is the surface energy of adhesion (per unit area) ω (of Dupré). It represents the local work dissipated during the decohesion process (i.e. at the particle pair or con-tinuum elementary area microscale). In several contact mechanics models of adhesion-decohesion, the surface energy ω is equal to the product of two other basic adhesive properties, namely the adhesion peak stress pin and the decohesion rupture gap γn, or rather a fraction of it (e.g. one half)