EXPERIMENT VALIDATION ON MODELING THEORY FOR RIGID-FLEXIBLE COUPLING SYSTEMS
刚柔耦合建模理论的实验验证

It's well known that the traditional hybrid-coordinate model of rigid-flexible coupling systems, i.e. the zero-order approximate dynamic model, has some flaws in some high speed cases. The present work presents a finite-element model for a multibody system consists of a rotating hub and a flexible beam with a tip mass on its tip. This theoretical procedure and the traditional hybrid coordinate approach are examined by comparing their numerical simulations with an experimental test. Based on deformation theory and geometric constraints, a second-order approximation for the displacement field is proposed and the dynamic stiffening is accounted for. Since the motion of the hub is unknown, the large overall motion of the reference frame of the beam is not prescribed and is affected by elastic deformation. In order to compare simulation results with experimental data, both viscous damping and air drag force have been introduced into this model. The experiment is carried out in a single-axis air-bearing testbed. The results demonstrate the validity of the developed model, while the traditional hybrid coordinate approach could lead to bad results for some high speed cases.