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#1 2018-05-17 15:02:24

dbpatankar
Member
From: Roorkee, Uttarakhand, India
Registered: 2010-05-22
Posts: 172

Dimension of stiffness matrix and load vector are inconsistant

Hi,

I was just trying to export the stiffness matrix and load vector after ASSEMBLAGE command.
I modelled a simple Euler-Bernauli beam (in 3D) with only one element.
So the resulting stiffness matrix should be 12 X 12 and load vector should be 12 X 1.

However, the stiffness matrix exported has the dimension 24 X 24 and load vector has dimension 12 X 1.
Why the stiffness matrix is larger than expected? Am I missing something here?

Attaching a sample model with comm and med files.

Please have a look and let me know.

Moreover, I would also like to know the node numbering associated with matrix elements. I guess it should be in NUME_DDL, but couldnt get any document explaining all the methods. dir() on the module does not list all the methods/attributes available. Is it documented?

With regards,


Attachments:
matrix_export.zip, Size: 2.47 KiB, Downloads: 96

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#2 2018-05-24 13:29:21

levesque
Moderator
Registered: 2012-01-26
Posts: 40
Website

Re: Dimension of stiffness matrix and load vector are inconsistant

For justification of the size of stiffness matrix see document R3.03.01 Dualisation of boundary conditions
It''s a general  principle for solving linear system with Code_Aster


Jean-Raymond Lévesque
Representative of [i]Code_Aster ProNet[/i]
[email]contact@code-aster-pronet.org[/email]

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#3 2018-05-24 16:07:23

dbpatankar
Member
From: Roorkee, Uttarakhand, India
Registered: 2010-05-22
Posts: 172

Re: Dimension of stiffness matrix and load vector are inconsistant

Thank you!

Any reference on node numbering/NUME_DDL part?

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