Reading the calculix manual, I found a card that allows to generate residual stresses at the beginning on the simulation.
CalculiX CrunchiX USER’S MANUAL version 2.13 (in page 291)
6.11.7 Initial(residual) stresses
In each integration point of an element a residual stress tensor can be specified
by the keyword *INITIAL CONDITIONS, TYPE=STRESS. The residual stress
should be defined before the first *STEP card.
and in page 406
Following line for TYPE=STRESS if USER is not specified:
Element number.
Integration point number. # (what is this?)
Value of first stress component (xx) in the GLOBAL coordinate system x-y-z.
Value of second stress component (yy) in the GLOBAL coordinate system x-y-z.
Value of third stress component (zz) in the GLOBAL coordinate system x-y-z.
Value of fourth stress component (xy) in the GLOBAL coordinate system x-y-z.
Value of fifth stress component (xz) in the GLOBAL coordinate system x-y-z.
Value of sixth stress component (yz) in the GLOBAL coordinate system x-y-z.
Etc.
Repeat this line if needed. The stress components should be given in the form of second Piola-Kirchhoff stresses.
...
The idea is to apply solely to one element (e.g. one C3D10 tetrahedron) an initial residual stress. Imagine that we have a cantilever beam, we select solely one element, and this element contains a residual stress due to some errors during a manufacturing process.
How can I simulate that?
I assume that the input file code should be something like that:
Code: Select all
*INITIAL CONDITIONS, TYPE=STRESS
22,?,(xx),(yy),(zz),(xy),(xz),(yz) # element 22 6 values of the stress tensor
28,?,(xx),(yy),(zz),(xy),(xz),(yz) # element 28 6 values of the stress tensor
33,?,(xx),(yy),(zz),(xy),(xz),(yz) # element 33 6 values of the stress tensor
...
Anyone knows or have experience about that?
If it is not possible to do that, is there any other way for simulating (initial) residual stresses?
I was thinking on applying a known pressure force to all faces of one element and then simulate using *perturbation card...
best regards,
Ekaitz.
EDIT: This question is related with my other doubts https://forum.freecadweb.org/viewtopic.php?f=18&t=31489 and https://forum.freecadweb.org/viewtopic.php?f=18&t=31421