A Dynamics Analysis Method for Flexible Multibody System Based on Null Space Symplectic Runge-Kutta Algorithm

For the dynamic analysis of flexible multibody system, it is essential to have the high accuracy and long-lasting numerical simulation with high computational efficiency. Existing modeling methods or numerical algorithms cannot achieve all of these targets at the same time. To solve these challenges, a novel dynamic analysis method is proposed by combining the Floating Frame of Reference Formulation with the Symplectic Runge-Kutta algorithm based on the Null Space theory in this paper. To verify this method, several numerical cases are carried out and the time step size for numerical convergence, actual computation time, iteration energy error, and constraint violations are evaluated. Compared to other modeling and computing methods, it is verified that this method has better numerical convergency, modeling versatility, computational accuracy and time stability preserving for flexible multibody systems at the cost of higher algorithm complexity and larger computation.