Steady-State Behaviour of a Solar Array System with Elastic Stops

Abstract

In recent years a method was developed by the authors for efficient analysis of the long term behaviour of mechanical systems with local nonlinearities under periodic excitation. In this method the linear parts of the system are modelled using the finite element method. In order to keep the cpu-time for the nonlinear analyses acceptable, the number of degrees of freedom (dof) of the linear part of the system is reduced using a component mode synthesis (cms) technique. The cms technique used is based on free-interface eigenmodes and residual flexibility modes. Eigenmodes are kept up to a user-defined cut-off frequency. Subsequently, the reduced linear model is coupled to local nonlinearities, such as nonlinear springs and dampers, dry friction elements, backlash etc. The model obtained in this way is analysed using a nonlinear dynamics toolbox, which among others contains solvers for the calculation of periodic solutions and their stability and a path following method. The approach outlined above is described in Fey (1992) and Fey et al. (1996) and was integrated in the finite element package DIANA (1997). Until now, this approach was applied to rather academic, archetypal problems in order to verify its value. The approach turned out to be very successful: numerical results were compared with experimental results and a good correspondence was achieved (van de Vorst, 1996, van de Vorst et al., 1996a, van de Vorst et al., 1996b).