This has taken a long time to verify against a commercial software suite Strand 7.
Enclosed is 3 zip files zipped into an over arching archive.
PlateVibration.zip are Mathcad worksheets.
References.zip are PDF references that show how finite elements work and some examples
Strand7_Files.zip is the commercial package files. A free viewer is available at
The files with extension lsl and nfl are log files and are text. nfl standing for natural frequency log shows the results.
In summary the Mathcad worksheets perform natural frequency analysis of a rectangular plate with varying support conditions and can plot mode shapes for each natural frequency.
It has reasonable accuracy.
This file shows two new things
a) How to clamp the top,bottom,left,and right edges of the plate as part of the finite elements.in terms of dx,dy at top of sheet. By altering these boundary restraint codes all the support cases in RICE0523.pdf tables can be achieved.
b) Comparison to RICE0523.pdf tables.
The file uses a poissons ratio of 0.3 so comparison to RICE0523.pdf tables is possible.
b) Comparison to RICE0523.pdf tables is good.