Impact of Control Surface Stiffness on Aeroelastic Divergence and Reversal

This study addressed a gap in traditional aeroelastic models by incorporating the finite torsional stiffness of control surfaces within an extended two-degree-of-freedom analytical framework. By deriving the governing equations and evaluating the static aeroelastic phenomena of Divergence and Control Surface Reversal, the study demonstrated the significance of including control surface hinge stiffness, which has been typically neglected or oversimplified in existing literature. The results show that ignoring the finite stiffness of the control surface can lead to nonconservative estimations, notably overestimating control surface effectiveness and the associated reversal speed. The analytical outcomes revealed that a decrease in control surface torsional stiffness relative to the main aerodynamic surface accelerates the onset of Control Surface Reversal. This finding underscores the importance of precise stiffness characterization in the design phase, especially for critical aeroelastic assessments