For Large-scale Movement Of The Flexible Beam And Flexible Sheet Metal Flexible Coupling Dynamics Modeling And Simulation,

In the project, many subsystems of complex structures can be simplified into flexible beam or plate undergoing large overall motions. The rigid-flexible coupling dynamics of these systems, flexible beams and thin plates in macro field and flexible beams in micro field, are studied in this paper. The traditional hybrid coordinate model is considered as a zero order approximation model and has limits to analyze the rigid-flexible coupling dynamics. Based on continuum medium mechanics, the coupling terms of deformation are included in the expression of longitudinal deformation, caused by transverse deformation. The governing equations of motion with the "dynamic stiffening" terms (referred as the first order approximation model) are established using assumed mode method and Lagrange's equations.The dynamics of flexible beam and thin plate in macro field are simulated respectively when the system undergoes large overall rotation or translation. The coupling effect of rigid motion and deformed motion is studied. It is shown that, the large overall rotation can result in dynamic stiffening and both phenomenon of dynamic stiffening and dynamic softening can occur in the flexible component when the system undergoes different acceleration of translation.The deformation energy of micro beam is obtained based on couple stress theory, considering size effect. The influence of size effect on the dynamic response and the resonant frequency of micro beam are analyzed at first. And secondly, the suitable range of zero order approximation model is determined, considering size effect at micro scale. Finally, the influence of size effect and coupling terms of deformation on the stiffness of flexible beam is analyzed.This research shows that, the traditional dynamic model can't correctly describe the dynamic behavior of flexible component under large overall motion because of the coupling of the rigid motion and the deformed motion. In order to describe the dynamic behavior correctly, it is necessary to establish the first order approximation model.