You can use any Printing value. This will not affect the results, but only the amount of information printed in the LST file generated by ATILA. The Geometry should clearly be set to 3D. The Analysis that we wish to perform here is a Modal Resantires, because this particular type of modal analysis takes into account the piezoelectric properties of the material. In particular, it computes the resonance modes, as well as the antiresonance modes, of the structure. Finally, the Number of Modes is set arbitrarily. However, here, because the model consists in a 3D structure that is free of mechanical conditions, the first 6 modes computed by the modal analysis will correspond to the 6 rigid-body modes of the structure. It is therefore recommended to use a number greater than 6. Here, we pick 20.
Note that the mesh density limits the number of modes that can be accurately computed. With the mesh we have defined, we cannot expect to accurately compute modes that display more thanhalf a wavelength in the thickness direction, or more than one wavelength in the width direction, or more than three wavelengths in the length direction.
Note also that computation time increases geometrically with mesh density and with the number of modes.