Description of joint constraints in the floating frame of reference formulation

This article presents the modelling principles of the joint constraints for flexible multibody systems. The joints are composed using three basic constraint primitives which are derived including their first and second time derivatives as well as the components of the Jacobian matrix. The description of the derived components of constraint primitives can be used to develop a library of kinematic joints to use in multibody codes. In this study, the equations of motion are defined using generalized Newton-Euler equations where the deformations are accounted for by using the floating frame of reference formulation with modal coordinates. The deformation modes used in the floating frame of reference formulation are obtained from the finite-element analysis by employing the lumped mass matrix. Dynamic analysis of a mechanism consisting of rigid and flexible bodies is used to illustrate the validity of the constraint formulation. © 2009 IMechE.