2. Experimental approach

Most mechanical tests on bonded assemblies, often erroneously referred to as "adhesion tests", stress the entire assembly: substrates, adhesive and interfaces (figure 1 ). The results of these tests, expressed in the form of a breaking force or stress, or even a critical rate of energy restitution G _c , are then representative of the overall mechanical behavior of the assembly at breakage. This behavior depends on the mechanical properties of the substrates, which must remain within the macroscopically elastic deformation range, of the adhesive in the form of a joint, and of the interfaces. Under these conditions, only destructive tests which promote interfacial substrate/adhesive failure by concentrating maximum stresses close to the interface...