Efficient parameter identification using generalized Polynomial Chaos Expansion – A numerical and experimental study

In order to validate numerical simulations, it is essential to compare calculated results with measurements. A common tool to increase the accuracy of the numerical simulation is model updating. The idea is to find better input parameters which describe the system more precisely by comparing the measurements and the numerical results, e.g. the modal properties. Finite element model updating is state-of-the-art and well described in literature. In this paper, an alternative computational method called Numerical Assembly Technique is used to calculate the natural frequencies, the mode shapes and the Frequency Response Functions. The generalized Polynomial Chaos Expansion is applied to increase the numerical efficiency of the model updating process. A stepped circular shaft is analyzed and it is shown, that the model updating process is not a straight forward technique. The input values of the parameter fit as well as the numerical model are limited. A solution which fits both criteria is described, and selected improvements are given.