Optimization process for correlation of experimental and numerical modal analysis

In the virtual vehicle development verification of the simulation models is essential for all further steps. In particular NVH models show complex dependencies to all sorts of simulation parameters. Optimization methods help to obtain better correlation in less time. The dynamic behavior of a structure is characterized by the Eigen -frequencies and their shapes of oscillation. The fundamental criteria for quantifying the correlation between test and simulation therefore are the frequency ratio of related modes and the conformity of the oscillation shapes numbered by the modal assurance criterion (MAC). Both aspects should be considered in the objective function. Setting up the optimization requires an extensive automation, since large amount of data and complex interconnections need to be treated in a robust way. The usage of Hyperworks tcl scripts enables automated definition of table entries for test data containing test frequencies and shape vectors, simulation frequency responses, mode specific displacement responses for measurement nodes, equation and responses for MAC calculation, as well as the equation and response for the very complex objective function. The optimization process shown in the paper is developed in Hyperworks and can be easily applied to a variety of NVH models independent of the model type, the number of modes, or the number of measurement points.

The Author

Dr. Martin Müller-Bechtel
Tecosim GmbH
Ferdinand-Stuttmann-Str. 15
65428 Rüsselsheim, Germany

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