ANSYS 12.1 - Modal & Symmetry Question 1

[KWilliston]

Hello Eng Tips,

I am using ANSYS 12.1 to obtain the mode shapes of a thin 2mx2m plate. This worked perfectly when using no symmetry BCs.

Now I am trying to obtain all these mode shapes/frequencies using quarter symmetry of the plate but when I setup the symmetry BC it seems to only have a few of the frequencies I am looking for.

I don't have much of a background in modeshapes/natural frequencies so any help is appreciated! I am not even sure if it possible to do this using quarter symmetry.

Thanks!

-Kyle

 

[kan123]

For a half model, you would need to run 2 cases -- one with symmetric BCs and one with antisymmetric BCs -- to capture all of the modes. With a quarter model, you'll need 3 runs: sym/sym, sym/anti, and anti/anti.

 

[KWilliston]

Thank you this worked perfectly!