Multifidelity component interface reduction and modal truncation augmentation

Abstract

SummaryA Hurty‐Craig‐Bampton (HCB) reduced order component can have unnecessarily large dimension if it contains many interface degrees of freedom. This is often the case for high spatial resolution models. Furthermore, for such high‐fidelity models, their static constraint modes can be expensive to compute. To overcome these problems, a component mode synthesis method with interface reduction is developed using multifidelity models. The interface reduction basis is computed from the assembled system by coarsening each substructure's mesh, but keeping the model resolution at the interface intact. It is shown that such a mesh coarsening has a small effect on the interface reduction basis quality. Using this reduction basis, the dimension of the static constraint modes problem can be reduced and the modes computed at a low cost. When few interface modes can be used without significant loss of accuracy, it is possible to enrich the HCB basis with modal truncation augmentation (MTA) vectors to increase accuracy at a small extra cost. The accuracy of a procedure that utilises MTA vectors together with the multifidelity interface reduction is investigated. The method's performance and accuracy are illustrated on a planar problem and a more complex problem from industry.