The recent transition to full composite fuselages is a major breakthrough in aeronautical design. To ensure satisfactory lightning protection, the electrical properties of the primary composite structure need to be improved and a design solution lies on bonding a metallic shnet to the fuselage. An important issue is the prediction of the aging behavior of this top layer when exposed to severe aging conditions representative of ight environment. Multiple aging mechanisms a ect this top layer made of thermoset resin and metallic shnet with complex geometry and a rst modeling strategy is a necessary starting point to better understand its evolution. This paper describes the overall phenomenology and the di erent mechanisms that can be expected in such a structure.