A Pretest Planning Method for Model Calibration for Nonlinear Systems
With increasing demands on more flexible and lighter engineering structures, it has been more common to take nonlinearity into account. Model calibration is an important procedure for nonlinear analysis in structural dynamics with many industrial applications. Pretest planning plays a key role in the previously proposed calibration method for nonlinear systems, which is based on multi-harmonic excitation and an effective optimization routine. This paper aims to improve the pretest planning strategy for the proposed calibration method. In this study, the Fisher information matrix (FIM), which is calculated from the gradients with respect to the chosen parameters with unknown values, is used for determining the locations, frequency range, and the amplitudes of the excitations as well as the sensor placements. This pretest planning based model calibration method is validated by a structure with clearance nonlinearity. Synthetic test data is used to simulate the test procedure. Model calibration and K-fold cross validation are conducted for the optimum configurations selected from the pretest planning as well as three other configurations. The calibration and cross validation results show that a more accurate estimation of parameters can be obtained by using test data from the optimum configuration.
KeywordsNonlinear model calibration Pretest planning Clearance Multi-harmonic excitation Fisher information matrix
- 7.Castro-Triguero, R., Friswell, M.I., Gallego Sevilla, R.: Optimal sensor placement for detection of non-linear structural behavior. In: Proceedings of the International Conference on Noise and Vibration Engineering (ISMA), Leuven (2014)Google Scholar
- 8.Yaghoubi, V., Chen, Y., Linderholt, A., Abrahamsson, T.: Locally non-linear model calibration using multi harmonic responses-applied on ecole de lyon non linear benchmark structure. In: Proceeding of the 31th the IMAC, Garden Grove (2013)Google Scholar
- 11.Ferreira, J.V., Ewins, D.J.: Algebraic nonlinear impedance equation using multi-harmonic describing function. In: Processing of the International Modal Analysis Conference, Orlando (1997)Google Scholar