Derivation of nondimensional rigid-body equation of motion and coupling with flexible body in ANCF

The absolute nodal coordinate formulation (ANCF) developed in the mid-1990s can express large rotation, displacement, and deformation in flexible body analysis. However, there is a disadvantage in that the analysis time increases owing to an increase in the degree of freedom. To address this problem, a nondimensional equation of motion was proposed, but existing research related to the nondimensional equation of motion is limited to a flexible body. Therefore, in this study, a nondimensional rigid body motion equation was developed, and a rigid body and a flexible body were combined using a nondimensional fixed joint. The numerical solution of the developed nondimensional equation of motion was verified using the existing problem. It was observed that when the number of elements is 200, the nondimensional equation of motion performs approximately 2.32 times faster analysis. Therefore, as the number of elements increases, the nondimensional equation of motion is more advantageous.