Numerical modelling of guided waves dispersion curves in an aluminium flat plate by finite element analysis

This work presents a practical approach to obtain the dispersion curves for a plate via numerical modelling using the commercial software ANSYS. The method is based on the dynamic analysis of the waveguide to extract the mode shapes (eigenvectors) for each resonant frequency (eigenvalue) from the natural frequency response without damping. Each eigenvalue provides a frequency and the dimensions of the model (wavelength), which are the basis of the dispersion curves. Then, an algorithm is developed in MATLAB to stack the different mode solutions with its respective frequencies using the modal assurance criterion. The data obtained is compared with the dispersion curves provided by the GUIGW software.