Flexible-body dynamics modeling of a vehicle moving on the rails of a structure

Abstract

The problem of dynamics modeling of a flexible structure that moves on the surface of another flexible structure is nominally beyond the scope of available commercial codes, and is addressed in the published literature only in a limited sense. The dynamics of the system comprising the space station and the moving mobile transporter, mated to the orbiter or to the payload-carrying robotic arm, offers related challenges. A novel analytical approach is presented that can be used to study the dynamics behavior of such time-variant structural systems as the mobile transporter during space station operation and/or assembly. The approach developed herein is based on the formation of a linear transformation that expressses displacement compatibility at the time-variant interface domain of two flexible bodies. The methodology is readily applicable to large structural systems. The required inputs that characterize the structural system constitute readily available finite-element data. A model reduction scheme is developed wherein component modes of the parent linear-time-invariant problem are employed. Numerical results are provided.