Free Vibration analysis

[Kazuya]

I'd like to run a free vibration analysis.
What I want to do is to specify the prescribed displacement
at all degree of freedom and then release the structure without
any external load.

So far, I tried
1. Static analysis with "Fix" constraints for fixed nodes and "sp"
constraints for disp-prescribed nodes. As for the constrain handler and
integrator, I used "Penalty" handler and "load controll".
2. invoke "wipe" command
invode "remove load" command
3. Transient analysis without specifying any load.

Is that correct things to do? I'm obtaining some strange results.

[fmk]

you don't want the wipe command (you are probably using the wipeAnalysis command anyway .. just a typo in your message) .. it removes all nodes, elements, constrainys, etc .. use
wipeAnalysis instead

should work fine otherwise

if not happy i suggest you test with a single dof system first .. then test with an elastic multi-dof system.