Aeroelastic Coupling of Hard Maneuvering Aircraft

The study presents an investigation of the coupled flight-mechanics–aeroelastic stability of the F-16 fighter jet during hard maneuvering. The paper provides an original derivation of the nonlinear coupled equations of motion utilizing a general six-degrees of freedom mass and stiffness matrices as extracted from finite-element modeling. The paper presents linearization of the coupled nonlinear equations of motion and their subsequent representation using modal coordinates, revealing new rigid-body-elastic modal coupling terms. The linearized system, with three of the coupling terms, was used in flutter analyses of a maneuvering F-16 with various store configurations to study the impact of load factor on flutter onset. A comprehensive survey of 2016 different store configurations highlighted the main contributors to variations in flutter speed. Future work will further explore the effect of rigid-elastic coupling terms in the linearized coupled EOM in modal coordinates on flutter characteristics and dynamic response, focusing on the significance of the different coupling terms in different applications.