Dynamic Simulation of General Flexible Multibody Systems*

Abstract

A formulation and associated solution method are presented for dynamic simulation of multibody systems consisting of rigid bodies, flexible bodies that undergo large gross motion accompanied by small elastic vibration, and flexible bodies that undergo large gross motion and geometric and material nonlinear deformation. This formulation combines the Cartesian rigid body formulation, the modal flexibility approach, and nonlinear finite element methods. Nonlinear kinematic constraints between bodies are enforced using the Lagrange multiplier method. Linear kinematic constraints between bodies are enforced by eliminating dependent generalized coordinates in an assembly process. The resulting differential-algebraic equations are solved using a method that is based on the generalized coordinate partitioning algorithm. The general flexible multibody dynamics formulation and solution methods are implemented by developing an integrated version of DADS and a pilot general-purpose nonlinear finite element analysis code. Numerical examples are provided to demonstrate the validity of the formulation and numerical methods.