Determining dynamic characteristics of bellows by manipulated beam finite elements of commercial software

A procedure for determining dynamic characteristics of bellows by manipulat ing certain parameters of the beam finite elements of I-DEAS Master Series 6 is presented. The method will work in any software in which these parameters can be set b y the user. Compared to a shell elements model the model size is reduced by at least a factor of 100. This is especially advantageous when the bellows is only a part of a system to be optimised with respect to overall design parameters. Stress in the bellows cannot be predicted by this method, but w hen the dynamic behaviour is known it can be used as input for stress calcu lations, if desired. In contrast to existing "semi-analytical" methods this method has the poten tial of considering axial, bending and torsion degrees of freedom simultane ously, and it facilitates the interaction between the bellows and the rest of the system, also modelled by beam or shell finite elements. The procedure is verified by experimental results from other investigators. (C) 2000 Elsevier Science Ltd. All rights reserved.