Rectangular plate natural frequency problem

[xyz1982]

Hi.

I have a problem with the results gained from a natural frequency simulation on a rectangular plate. The results gained are completely different to the ones obtained for the same plate through the theoretical equations. I would be very grateful if someone could take a look at the Inventor file and let me know what I am doing wrong.

I have attached a Microsoft Excel file with the results from the theoretical equations using the same material properties. (The frequencies are in rad/s in the Excel spreadsheet whereas they appear in Hz in Autodesk.)

The corresponding equations used can be found in the Word file.

I am very grateful for your help. Please ask if you need more information or have questions.

Thanks,

Sam