KINEMATIC MODEL OF A MULTIBEAM STRUCTURE UNDERGOING LARGE ELASTIC DISPLACEMENTS AND ROTATIONS - PART ONE - MODEL OF AN ISOLATED BEAM

This article presents an alternative approach to kinematics modelling of a multi-body system constituted of deformable slender beams is pres ented. We begin by pointing out that the classic modelling approaches that are programmed today in the simulation softwares of flexible mult ibody systems do not take into account the finite rotations which occu r during the motions of a large space structure. Contrarily to the usu al alternatives based on quadratic approximations of rotational fields , the proposed approach uses a closed exact form of the finite rotatio n field. This field is expressed as a function of the usual geometrica l variables of an Euler Bernouilli beam. This notably permits one to r each the exact non-linear displacement field. Finally those results wi ll be applied, in a second part; to the computation of the kinematic m odel of a poly-articulated system and in the future to the dynamic mod elling. (C) 1998 Elsevier Science Ltd. All rights reserved.