Influence of Connect Method between Elements in ANCF on Dynamic Behavior of Flexible Multibody Systems

Recently, large-scale infrastructures including flexible multibody systems with many constraints are implemented. The vibrations generated on these structures may threaten safety. Thus, the establishment of calculation technique of flexible multibody systems with many constraints is quite important to accurately simulate dynamic behavior of such structures. In this study, the absolute nodal coordinate formulation (ANCF), which is a non-incremental nonlinear finite element method was used. The two type of methods to connect adjacent elements was used: constraint and superposition methods. In the constraint method, adjacent elements are intentionally connected by constraint equations to verify calculation stability and accuracy of flexible multibody systems with many constraints. On the other hand, two adjacent nodes are regarded as a single shared node in the same way with the classical finite element method in the superposition method. Three benchmark tests (large rotation problem, large deformation problem, large rotation and deformation problem) have been conducted. In the large rotation problem without large deformation, the calculation results obtained by the constraint method show good agreement with that obtained by the rigid-body model and the superposition method although the Baumgarte’s stabilization method is not introduced. Moreover, almost same feature was obtained in the large deformation problem without large rotation. In contrast, the difference between the constraint and superposition methods increases with time in the large rotation and deformation problem. The numerical error in the constraint method was appropriately improved by introducing the Baumgarte’s stabilization method.