Dynamic interval analysis of FE models with uncertain substructures

The exponential growth of the computational capacity has, amongst other things, enabled the design engineer to include non-deterministic properties in the numerical simulation and validation of new designs. In this context, the interval concept has been introduced for the description of incomplete data, subjective knowledge and modelling uncertainties in a non-probabilistic manner. The use of the interval concept in the finite element context has led to the development of the interval finite element method for eigenfrequency and frequency response function analysis. For industrially sized models with a large number of uncertainties, the computation time of these methods can be considerable. A reduction in calculation time can be achieved by the substructuring of large models into substructures, which are then independently processed and reduced, and afterwards recombined. The aim of the presented work is to combine the interval finite element method for dynamic analysis with the Craig-Bampton component mode synthesis substructuring technique, in which the static and dynamic behaviour of each substructure are represented by a set of component modes. Special attention is paid to the consequences of uncertain parameters on the numerical representation of an uncertain substructure. A numerical case study is presented to illustrate the concepts used in this paper.