Application of deformable-body mean axis to flexible multibody system dynamics (Q1065572)

While a body-fixed axis is commonly employed as a reference for rigid components, a moving axis is suggested for flexible bodies that undergo large rotations. There are, however, an infinite number of arrangements for the body axes of flexible components. In order to define a unique displacement field, a set of reference conditions that define the nature of the body axis have to be imposed. These reference conditions are mainly dictated by physical considerations. In multibody systems the motion of flexible bodies are constrained by and coupled with the motion of other components in the system through a set of nonlinear constraint equations that describe joints between different bodies. In this paper the problem of selecting an axis for flexible bodies is addressed in the frame of a general finite element development for both planar and spatial multibody systems. A body reference satisfying the mean-axis conditions has been selected for a detailed discussion.