Interface reduction in flexible multibody systems using the Floating Frame of Reference Formulation

The influence of interface reduction on the dynamics of flexible multibody systems has not been well investigated and the conventional multipoint constraints still suffer when applied to multibody systems. Here, we propose a novel approach to derive rigid and interpolation multipoint constraints exploiting the role of the reference conditions, used in the Floating Frame of Reference Formulation to cancel rigid body modes from the elastic field. Since the connection of the reference conditions to the multipoint constraints seems to be limited to the free-surface case, the proposed formulation combines the interface reduction problem to create a novel Component Mode Synthesis method able to work with any reference condition. Two case studies are presented to show the differences between models with different combinations of reference conditions and multipoint constraints.