Background: Non-destructive structural health evaluation of thin-walled components on the basis of Lamb wave propagation is a widely used approach. However, most current methods to measure the dispersive behavior of Lamb waves are time based approaches and are not easily capable of high automation to measure influences on the wave propagation along a wide range of frequencies.
Objective: Develop and validate a highly automatable method to measure Lamb wave dispersion diagrams with high accuracy. To be able to broadband examinate influences, which have only a small effect on the wave propagation.
Methods: The use of frequency based approaches like the 2d Fourier transform is a known method to measure Lamb waves. This investigation tries to bring together the advantage of the high automation as well as the high accuracy this method offers, by taking into account a non-uniform distribution of the measurement points and using particularly suitable excitation signals for high accuracy.
Results: The here stated method is capable of automatically creating dispersion diagrams for Lamb waves with high accuracy, automation and reproducibility. The experimental results are compared with analytical results and are in good agreement.
Conclusions: This investigation shows 2d Fourier transform as a method to create dispersion diagrams of Lamb waves is an accurate and especially highly automatable approach with high accuracy.