Novel experimental procedure and determination of full displacement fields of delaminating composite layer interfaces for evaluation of the mode II cohesive law

A novel mode II fracture test setup based on a simple tensile loading scenario with a discontinuous ply specimen is proposed in the paper as the first step towards determination of the cohesive law of composite layer interfaces. Key outputs of the procedure are the full displacement fields obtained by correlation of high resolution SEM images taken during in-situ tensile tests. Analysis of the full displacement fields at subsequent stress levels allow for unique analysis of the damage zone and direct determination of the displacement jumps across the interface. The next phase of the work is the evaluation of the shear stresses at the interface necessary to determine the cohesive law.