Hi kellnerp,
just a line to say thanks for your effort to shed some light on this matter, even if we havent found the reply !
Just to reply to the points in your last email , NO I dont have solidworks. All I have is a mech analysis report with a statement concerning the model checking.
As for...
I can't answer your question.
This model (and related analysis) comes from and is analysed by a supplier, I am just reviewing the analysis work. We have a detailed checking procedure which they must satisfy and which they must satisfy.
We do not have solidworks/COSMOS at all ! Hence we cannot...
Yep thats it. Stress-free =free-free
Non-zero RB modes means the damn thing is tied down somewhere when it shouldn't.
Whoa boy !
You're talking to a NASTRAN man here, used to problems (which all these damned problems have eh ... they all ought to be exorcised :-) of a different kind.
I didn't...
No, this can't be the explanation. Whilst individual points have no rotational dof this doesn't mean that the whole structure doesn't have rigid body modes !
There are both solids and plates in these models i.e. its a mixed shell/solid model.
Here is the exact 'explanation' given when the model...
Hi,
I maybe didn't put my question very clearly. The analysis is a free-free modal analysis, so it is expected to have x6 zero frequency modes. The analysis actually produces the first 6 modes, 3 with frequencies tending towards 0.0 but 3 others at 6 Hz, 14 Hz and 40 Hz. It is claimed these last...
Hi everyone,
I have a question relating to checking COSMOS models and in particular running a model free-free modal analysis.
A model has been sent to me at work with the results of a free-free modal analysis and there are 3 rigid body modes (translational but the following 3 modes are about 6...
