H. De Gersem, Interval component mode synthesis procedure for the dynamic analysis of large FE models, 2008

Abstract

The interval finite element (IFE) method enables to examine the effect of model uncertainties on the structural behaviour of new products and constructions. The method, however, requires a large number of crisp, classical finite element (FE) analyses, each time for a new set of values for the considered model parameters, and is hence computationally expensive. As a result, the applicability of the IFE method for industrial design simulation and validation is still limited. This dissertation aims at a substantial reduction of the computational cost for dynamic analyses of large non-deterministic FE models by the combination of the interval finite element method with the component mode synthesis (CMS) technique. This work describes a novel methodology for the efficient application of this substructuring technique in the presence of interval uncertainties. The developed interval component mode synthesis procedure applies an approximate reduction of a non-deterministic substructure, in each of the FE analyses in an interval procedure. The use of approximations of component modes of uncertain substructures avoids the need for expensive exact recalculations, and as such allows the full exploitation of the computational efficientcy of the component mode synthesis technique in an IFE analysis. A general concept for the approximation of non-deterministic component modes is proposed, and the applicability of three different variants of the methodology is examined, for global as well as local model parameters, and for small and large uncertainty intervals. The results of the two presented validation examples demonstrate that the proposed simple and transparent mechanism for the propagation of uncertainties through the CMS procedure offers a valuable compromise between efficiency and accuracy.

Order Code

Code: 08D07