Towards 'OPTIFLAP': Preliminary Structural Sizing Methodology for Trailing-Edge High-Lift Systems

This article proposes an efficient approach in preliminary sizing of composite flaperon structures using beam element solvers, in place of finite elements. Unlike traditional analyses that primarily address aerodynamic loading, the proposed methodology also accounts for kinematic failure load cases, enabling a more comprehensive assessment. A flaperon geometry - with varying cross-sections and thicknesses - is idealised into a beam element model with an appropriate node distribution. Structural responses to applied loads are then used by an optimisation process to size the structure, ensuring compliance with deflection, strain-failure, and buckling criteria. This streamlined workflow supports rapid trade studies, facilitating early identification of optimal design features and providing valuable insights during the preliminary design phase. The study demonstrates how this method can be applied to evaluate different material systems and highlights the lightweight benefits of spanwise thickness variation.