Modeling and Vibration of an Advanced Tilt-Rotor Wing System

Problems related with the mathematical modeling and eigenvibration of a tiltrotor aircraft-wing system built up of anisotropic composite materials are investigated. A wing- mounted rotor, which can tilt from the vertical position to a horizontal one, is mathematically modeled and analyzed from the vibrational point of view. In this sense, its behavior is analyzed as a function of the mass, size, mass moment of inertia, and tilt angle of the spinning rotor and of its location along the wing span. As concerns the aircraft wing, this is modeled as a thin-walled beam of arbitrary cross-section contour having a circumferentially uniform stiffness configuration that induces elastic coupling between flap- lag-transverse shear on one hand, and between extension-twist, on the other hand. Numerical simulations are provided and pertinent conclusions are outlined. Nomenclature ij a = 1-D global stiffness coefficients i b = mass terms L = wing span θ = ply angle ∆ = Dirac delta function ) ,