I did some FEA simulation of fused silica disks, to identify the lowest usable eigenmode. By usable I mean a mode that has zero elastic energy stored in the center.
Diameter |
Thickness |
Frequency |
75 mm |
1 mm |
2500 Hz |
100 mm |
0.4 mm |
564 Hz |
200 mm |
0.4 mm |
141 Hz |
75 mm |
0.12 mm |
293 Hz |
In the attached figures, the dfisk deformation is shown exaggerated, and the color map shows the elastic energy density. All results are obtained with COMSOL/MATLAB, the disk are constrained at a point corresponding to the center of the lower surface. No gravity. |