Modelling of contact dynamics of two flexible multi-body systems

Details of contact dynamics of two flexible multi-body systems (e.g. a spacecraft-mounted manipulator capturing a flexible satellite) are considered in this paper. The components undergoing direct contact (e.g. the end-effector of the manipulator and the grapple surface) are modelled using the finite element method that incorporates large rigid body displacements, while the rest of the system is handled through the usual flexible multi-body formulation. The basic condition of the contact is that no material overlap can occur; this condition is expressed in terms of a set of algebraic constraint equations. Thus, the system dynamics is described by two sets of differential equations (one for the multi-body formulation and the other for the finite element nodal displacements of the contacting surfaces) subjected to a set of algebraic constraint equations. A procedure to solve this system of equations is proposed in the paper. A typical scenario involving capture of a flexible satellite using a manipulator is considered and computer simulation results are presented. (C) 2000 Elsevier Science Ltd. All rights reserved.