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This paper reports on test-analysis correlation and model updating activities carried out in the context of the European research project “HPC-VAO” (ESPRIT Project nr 20074, High Performance Computational environment for Vibro-Acoustic Optimisation). The central aim of the project is the implementation of a state-of-the-art CAE environment to support design optimisation in the field of NVH engineering. A specific objective covers the validation of the simulation models that are used in the vibro-acoustic optimisation framework. The validity and reliability of these models can be drastically improved by application of ‘model updating’ techniques. Whilst much research has been done in this field in the last decade, the number of cases where the technique has been used on industrial applications are slowly but steadily growing.

This paper presents a model updating method based on experimental receptances. The presented method minimises the so called ‘indirect receptance difference’. First, the reduced analytical dynamic stiffness matrix is expressed as an approximate, linearised function of the updating parameters. In a numerically stable, iterative procedure, this reduced analytical dynamic stiffness matrix is changed in such a way that the analytical receptances match the experimental receptances at the updating frequencies. The updating frequencies are a set of selected frequency points in the frequency range of interest. Some considerations about an optimal selection of the updating frequencies are given. Finally, a mixed static-dynamic reduction scheme is discussed. Dynamic reduction of the analytical dynamic stiffness matrix at each updating frequency is physically exact, but it involves a great computational effort.