Abstract: Diamond Wings, Strut- and Truss-braced Wings, Box Wings, and PrandtlPlane, the so-called "Joined Wings,'' represent a dramatic departure from traditional airplane configurations.
Joined Wings are characterized by a structurally overconstrained layout which significantly increases the design space with multiple load paths and numerous solutions not available in classical wing systems.
Researchers showed that the geometric structural nonlinearities may play a complex role in the static and dynamic aeroelastic stability properties and responses of these systems. Stiffening/softening effects, flutter and Limit Cycle Oscillations are observed, possibly followed by a loss of periodicity of the solution as speed is further increased. In some cases, it is also possible to ascertain the presence of period doubling (flip-) bifurcations.

The fluid-structure energy exchange and its effects/interpretation on the dynamic stability will also be presented.

Bio: Luciano Demasi received his Ph.D. from Politecnico di Torino in 2004 and is an associate professor in the Aerospace Engineering Department, San Diego State University. His research interests cover the areas of aeroelasticity, composite structures, aerodynamics and innovative wing configurations