Mechanical Behavior of a Fuselage Stiffened Carbon-Epoxy Panel under Debonding Load

The present project sets out the analysis of mechanical behaviour of a carbon-epoxy stiffened panel under bending load. For this purpose, the National Polytechnic Institute of Mexico counts with a non-airworthy B727-200 as experimental platform. The first step was to calculate the aerodynamics loads and flight envelope of the aircraft. Secondly, the selection of the fuselage section is performed in order to identify an adequate stiffened panel for the study. The structural elements of the panel, skin and stiffeners were manufactured by VARTM and glued with high strength adhesive. The load, in bending condition, was imposed by a structural testing machine in order to emulate, at lab scale, the flight conditions responsible for debonding the stiffeners from the skin. The displacement field was determined by Digital Image Correlation (DIC) and the strains values at key zone of the fuselage by gages measurements. Finally, the failure mechanisms were analyzed with the goal to improve the knowledge of the stiffened-skin glued joint solution.