  Fiber metal laminates (FML) are of high interest for lightweight structures
as they combine the advantageous material properties of metals and
fiber-reinforced polymers. However, low-velocity impacts can lead to complex
internal damage. Therefore, structural health monitoring with guided ultrasonic
waves (GUW) is a methodology to identify such damage. Numerical simulations
form the basis for corresponding investigations, but experimental validation of
dispersion diagrams over a wide frequency range is hardly found in the
literature. In this work the dispersive relation of GUWs is experimentally
determined for an FML made of carbon fiber-reinforced polymer and steel. For
this purpose, multi-frequency excitation signals are used to generate GUWs and
the resulting wave field is measured via laser scanning vibrometry. The data
are processed by means of a non-uniform discrete 2d Fourier transform and
analyzed in the frequency-wavenumber domain. The experimental data are in
excellent agreement with data from a numerical solution of the analytical
framework. In conclusion, this work presents a highly automatable method to
experimentally determine dispersion diagrams of GUWs in FML over large
frequency ranges with high accuracy.
