On the Use of Double-Double Laminates to Improve and Innovate the Design of an All-Composite Wing Box

This work focuses on the study and application of an innovative design philosophy for composite structures, specifically suitable, but not limited, for aeronautical applications. Recent studies have shown that some classes of fibre-reinforced composite materials can be treated almost in the same way as isotropic materials, regarding the number of variables to be taken into account in the design phases. This is made possible by the definition of the Tsai’s Modulus and the concept of the Master ply. The new laminate families resulting from the application of these two concepts have been named Double-Double. These new design methodologies have been applied to a regional jet composite wing-box test case to evaluate their flexibility and robustness as well as their benefit in terms of structural mass reduction.