Electronic International Standard Serial Number (EISSN)
Structural geometrical nonlinearities strongly affect the response of joined wings: it has been shown that buckling evaluations using linear methods are unreliable, and only a fully nonlinear stability analysis can safely identify the unstable state. This work focuses on the understanding of the main physical mechanisms driving the wing system's response and the snap-buckling instability. Several counterintuitive effects typical of unconventional nonplanar wing systems are discussed and explained. In particular, an appropriate design of the joint-to-wing connection may reduce the amount of bending moment transferred, and this is shown to eventually improve the stability properties, although at price of a reduced stiffness. It is also demonstrated that the lower-to-upper-wing stiffness ratio and the torsional-bending coupling, due to both the geometrical layout and anisotropy of the composite laminates, present a major impact on the nonlinear response. The findings of this work could provide useful indications to develop effective aeroelastic reduced-order models tailored for airplane configurations experiencing important geometric nonlinearities such as PrandtlPlane, truss-braced and strut-braced wings, and sensorcraft.