Late Late Summer School Code-Aster

Hi Ing Ackva

In this structure ( attachment ) I consider 3 hypotesis of FEA analysis, from simpler to more detailed, here it goes:

1. Model as a 3D frame of beams with a shell, considering infinite stiffness at the connections bettween beams, and between shell/beams.
This can be modelea with linear/quadratic beam elements and linear/quadratic/high order shell elements ( if I want to consider a large displacement geometrically non linear analysis )

2. Model as a 3D frame of beams with a shell, considering finite stiffness at the connections described, introducing spring elements, 6 per connection, 3 for translation and 3 for rotatiom, per point connection at each pair of beams or beam/column and specifying a simply supported, or a full restrained BC condition for the shell respective of the supporting beams.

3. Model as a structure of 3D solids for beams/columns to account for the stress concentration effects caused by the bolt prestress in the connection, 2D elements for shell, and simple beam elements rigidly linked to nodes in the connected structural elements ( beam/column, beam/beam and beam/shell ) preloaded with tension, to account for the bolts.

This is, i believe, the most realistic approach, since i do not know the spring constants introduced by the bolted connections, and, contrary to model #1, the connection is compliant, so model #1 represents a structure that is stiffer ( less diplacement magnitude under load ) than the one I wish to analyze ( FE analysis codes solve the problem that one specifies, not what one "has in mind...", this is why one should always beware of the "illiterate" use and abuse of engineering analysis codes... IT IS DANGEROUS, ... i mean, bridges can collapse, airplanes may fall... etc. )

As far as i know ( I may be wrong of course... ) both Salome-Meca and Salome will allow me to solve #3, not #2 or #1, although Code-Aster can solve #1, #2, and #3 and even include contact conditions among structural elements.

This is why I will take the Code Aster Summer School.

If you want, I can solve for this problem using a commercial FE code like ADINA, so that we could compare results... or I can send you the .dat and the .in file of ADINA ( if you have it licensed ) so that you compare them...

Although the material library of Code Aster is way much vaster than ADINA's...

And I believe that GIBI is a better mesher than the internal mesher of ADINA...

As for the analysis types, can Code Aster perform Static large displacement ( geometrically non linear ), eigenvalue modal analysis, or eigenvalue buckling analysis besides of Static small displacement ?


Best regards


PS:

Forgot to attach the Loads in this pdf as well as the bolt hole locations in the shell...

I will reattach in a few hours... as soon as I get back to my win PC where I have Autodesk Inventor...

Alex <br /><br />Post edited by: Alex, at: 2009/09/17 18:07

Hi Alex,

Your complete project will take too much time to be an exercise in our seminar. We point to train the features and methods of Code-Aster using quite small models, rather than completing projects. Of course, participants learn to model beam, shell, 3D-elm, springs, liaisons etc. which will be useful for their project work.

Your 3 models are of course all solvable with Code-Aster, but some aspects may be difficult to prepare (mesh) using Salome.

best regards, Johannes Ackva
______________________________________________________________________
Ingenieurbüro für Mechanik Tel 0049 (0)9832 708152
Dr.-Ing. Johannes Ackva
Markgrafenstr. 21
D 91717 Wassertrüdingen

www.code-aster.de

Hi Ing Ackva

Thanks for your reply.

You mean to say that either my three models of this structure are solvable with aster ( Multi-element structures (beams+springs+shells+etc ) with contact )

Ok, this is an important feature for a practical &quot;usability&quot; of a FE code in practical, &quot;real world&quot; problems.

What about the analysis model :

1. Static vs implicit dynamic vs Explicit Dynamic
2. Eigenvalue modal analysis vs eigenvalue buckling/collapse analysis
3. Material nonlinearity ( I know aster does this ) vs geometric nonlinearity in large strain/displacement analysis ( creep/viscoplastic flow )

It would be interesting to know this, one more thing, besides of the documentation... ( quite large, i must agree ) are there any books/tutorials on using Code-Aster ?

Will I receive some kind of certificate of attendance to the Late Summer School Code Aster ?

These things are good to attach to the resume, besides of an MSc in Mechanical Engineering...

Once again thanks for your clarifications.

BRGDS

Alex

Dear Alex

&quot;What about the analysis model :
1. Static vs implicit dynamic vs Explicit Dynamic
2. Eigenvalue modal analysis vs eigenvalue buckling/collapse analysis
3. Material nonlinearity ( I know aster does this ) vs geometric nonlinearity in large strain/displacement analysis ( creep/viscoplastic flow )&quot;

Can all be done with Code-Aster, but not all are treated in this course, see course desctiption (attached)

&quot;It would be interesting to know this, one more thing, besides of the documentation... ( quite large, i must agree ) are there any books/tutorials on using Code-Aster ?&quot;

The main doc material of the course will be commentarized example files which explain the use of Code-Aster commands

&quot;Will I receive some kind of certificate of attendance to the Late Summer School Code Aster ?&quot;

Yes

For further clarifications please contact me on my private e-mail or phone (www.code-aster.de)

Best regards, Johannes Ackva