Visualizing the results of FEAP in GiD

[Ken Lippmann]

Dear Prof. Taylor,

Ich use GiD to visualize the results which I got from FEAP. However, I have some weird results that I can not explain by myself.

In my problem, I created a mesh which were formed by creating some blocks and merged together by using TIE command. However, when I visualized the displacements, there are several gaps between blocks.

Secondly, with the stresses field, I have checked the order of Gauss points in  FEAP and GiD and I see they have the same order. But I got discontinuities in stress field which can not happen in my problem.

Please have a look at the attached file of this email, you will see the problems which I get now and give me your advice to solve these problems.
It would be a big help for my case.

Kind regards,

Ken Lippmann

[FEAP_Admin]

The first thing you should do is make sure that the computation has been performed correctly by FEAP.
Check using FEAP's own graphics if there is a break in the mesh.  If not, then the problem lies with GID or
with your FEAP-to-GID interface.  If you see a break in the mesh with FEAP's own graphics, then you should
look in the output file, Oxxxx, to see which nodes have been tied.  It is possible that you are expecting nodes
to be tied together but they are not because they are outside of the default gap tolerance (which you can increase
if you need to, see the manual) or because you have input the TIE command incorrectly and nothing is being tied.
The same comments hold for the stress plots.  First try plotting with FEAP to see if the stresses are correct and the
plot with GID.  Note that FEAP's stress plot by default is an L2 smoothed stress field; if you use ESTRess instead you
will get an unsmoothed stress field.

[Prof. R.L. Taylor]

Another possibility is that GiD keeps all the nodes.  FEAP keeps the node numbers from ties but does not use them.  Instead it renumbers the elements with the numbers remaining after ties and  uses only these.  If you are exporting the mesh data to GiD before the ties are accomplished then you will get unusual results.  One option is to use feap to generate the mesh, do the ties and then output the mesh using the solution command OUTM.  Rerun feap to check that the file is correct.  does this fix the problem?

[Ken Lippmann]

Dear FEAP_Admin, dear Prof. Taylor,

Thank you very much for your advice. The problem I got is exactly what you mentioned. I follow your guidance and now the problem is solved.

Best regards,

Ken Lippmann