STEERING OF FLEXIBLE MULTIBODY MODELS WITH APPLICATION TO THE SIMULATION OF MANEUVERING FLIGHT

Nonlinear ∞exible multibody dynamics enables the high-fldelity simulation of rotorcraft vehicles. In this work we focus on the problem of simulating extreme maneuver- ing ∞ight conditions. In fact, limiting design factors such as maximum loads, vibrations, noise, etc. are encountered in the maneuvering ∞ight case and at the boundaries of the ∞ight envelope. The approach here proposed is based on a multiscale approach. A coarse level ∞ight mechanics model of the vehicle is used for solving a generalized trajectory op- timization problem that yields the ∞ight path and the controls that ∞y the vehicle along it. This problem is formulated as an optimal control problem, but it is manageable at a reasonable computational cost since only a coarse model with few degrees of freedom is used. The computed controls are then used for steering a flne scale aeroelastic model which is based on flnite element non-linear multibody dynamics. Matching of the trajec- tories ∞own by the two models is here obtained by means of parameter identiflcation of the ∞ight mechanics model. Selected critical rotorcraft maneuvers are analyzed in order to demonstrate the efiectiveness of the proposed methodology.