A dynamic model of spatial flexible revolute clearance joint via ANCF in flexible deployable system
摘要
Spatial flexible revolute joints are key components of space deployable devices such as the solar array system, in which a long shaft passes through multiple soft holes sequentially to achieve a long-distance flexible connection. However, complex local contact states exist in the motion of flexible jointed array system because of the coupled deformation of flexible parts with flexible clearance joints. In this paper, an equivalent dynamic model of spatial flexible revolute clearance joint is proposed to characterize the nonlinear coupling deformation and local contact of flexible shaft-holes. Firstly, the nonlinear behavior of the flexible revolute clearance joint is represented by utilizing the absolute nodal coordinate formulation (ANCF). The local position and relative distance of joint are defined and the nonlinear stiffness is introduced to characterize the local contact and separation states of the flexible joint. The coupling deformation conditions of the jointed parts are deduced based on the geometrical relationship, and the nonlinear elastic force of the flexible revolute clearance joint is derived. The dynamic equations of the flexible multibody system with flexible revolute clearance joint are established. In the case study, flexible jointed plate system and solar array system with flexible revolute clearance joint are presented. The accuracy of the proposed model is verified by the simulation and experiment. The effects of joint clearance on the deformations and dynamic characteristics are studied. The results show that uneven deformations and disturbed motions of the jointed plates are caused by the nonlinear local contact of the flexible revolute clearance joint.