: This project has the objective of developing a new generation of polymer composite materials with hybrid fibres based on multi-scale analysis and optimization. In this context, the use of multi-scale approaches, which transfer information between different scales, can provide a deeper physical insight into the material mechanical behaviour and offers the possibility to tailor new composite materials by manipulating their microstructure via numerical simulations guided by optimization methods. Therefore, new optimal design methodologies for composite materials and structures, both in its essential optimal design and also on its capabilities to characterize the material behaviour, including failure mechanisms, are required for this purpose. The main structural applications addressed are laminated composite structures used in aerospace applications, where the goal is to identify not only the best arrangement of layers, but also the optimal fibre hybridization of the composite material used in each layer. A structural baseline demonstrator, defined in collaboration with Airbus, is planned to assess the analysis and design model practical impact and relevance.