Nonlinear finite element aeroelastic analysis of multibay panels in supersonic flow regime

Aircraft wing and fuselage panels are often built in multibay configurations. Aeroelastic studies on multibay panels in supersonic flight were addressed by many authors in the past century under the assumption of linear structural behavior, therefore unable to assess the amplitude of the limit cycle oscillations. This work contributes to the study of multibay panel flutter by extending the model to account for geometrical non-linearities, and also by using direct time integration without any sort of linearization or eigenvalue assessment procedure. Results generated for two- and three-bay panels reveal that the single-panel model can drastically underestimate the maximum displacements at the structure, which is critical for structural design and fatigue-life estimation. Also, for the first time, the existence of discontinuous bifurcations has been observed in the limit cycle amplitude diagrams for different multibay arrangements. Such bifurcations have been proven to be directly related to the nonlinear coupling between adjacent bays and the coexistence of different stable limit cycles sensitive to initial disturbance.