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A crack propagation test is performed under mixed mode I and mode II condition along the interface of an aluminium/aluminium joint bonded with EA9321 epoxy paste using a Mixed Mode Bending (MMB) apparatus. Supplementary instrumentation is added to the system for a finer test control but also for a precise probing of the cohesive forces distribution in the adhesive at the vicinity of the crack tip. In Addition to the usual load cell and displacement sensors which are used for measuring the applied force and specimen mid-span deflection and opening, Digital Image Correlation technique is used for full field observation of the specimen deformation near the crack tip position. Finally, backface strain monitoring technique is used to probe with a high sensitivity the presence of cohesive force gradient near the crack tip. All the experimental results are compared with the one obtained with a simple model consisting of two Timoshenko Beams bonded with an elastic interface. Satisfying agreement between theoretically and experimentally determined displacement fields which indicates that such measurement should allow the evaluation of effective stiffness. On the contrary, backface strain monitoring measurements evidence significant difference between the two which indicates that this technique should enable a finer characterization of the non linear behaviour of the adhesive layer.