A time-domain substructure synthesis for finite rotations of flexible mechanical systems

School of Aerospace Engineering, Beijing Institute of Technology, Zhongguancun South Street 5, 100081 Beijing, China

Abstract

This paper presents a floating IBS method for dynamic prediction of structures with finite rotations. The conventional IBS (impulse-based substructuring) method is efficient and accurate in structural transient impact analysis. When facing about finite rotations, the conventional IBS method will generate unreasonable results due to the lack of consideration of geometric nonlinearity. In this paper, the idea of floating frame of reference is introduced. The motions of structures are divided into the moving of floating frame of reference and local vibrations which are described using the idea of IBS method. Two numerical examples validate that the proposed method is available for unconstrained single-body system (free-free rotating beam) and constrained multibody system (a slider-crank system). Meanwhile, to some extent the local elastic vibration degrees of freedom can be reduced by employing interpolation matrixes