Interval model updating of the AIRMOD structure

Abstract

This paper considers the application of interval model updating to the estimation of uncertain parameters of an AIRcraft MODel (AIRMOD) structure. The AIRMOD structure is a replica of the GARTEUR SMAG19 benchmark and was constructed at the German Aerospace Centre (DLR) in Göttingen for investigation of aeroelastic phenomena and uncertainty effects. A series of modal tests were carried out to determine the variation of measured modal data (natural frequencies and mode shapes) due to repeated disassembly and reassembly of the structure. Uncertainty in joint stiffness parameters resulting from the disassembly and reassembly is responsible for observed variability in modal data. A detailed finite element (FE) model of the AIRMOD structure is prepared and parameterised for the purpose of interval model updating, which is then carried out using a meta-model that provides a mapping between the parameters of the model and the predicted natural frequencies and mode shapes. The method is shown to be capable of identifying the interval updating parameters efficiently and accurately.