Hi all,
I have a simple question about loading to a restart from the solution.
First, I have mechanical results from a previous compute (strain,stress,dispacement), carried out in step 1.
Second, I'd like to restart from the last step of these results with new boundaries : no specific loading, only new blocked boundaries:
My questions are :
- are the stresses in the structural part considered as loading ?
- should I apply a loading as a force field ?
Thank you for your advice concerning this post.
Restart
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Re: Restart
Chapter 3
https://www.nic.funet.fi/pub/sci/physic ... Manual.pdf
You have to tell Elmer to save the restart file in the first analysis.
I have done this with transient, in 1 solution, have not tried it in restart.
In transient I apply the load for x amount of time, then let it go.
viewtopic.php?p=20818&hilit=abaqus#p20818
https://www.nic.funet.fi/pub/sci/physic ... Manual.pdf
You have to tell Elmer to save the restart file in the first analysis.
I have done this with transient, in 1 solution, have not tried it in restart.
In transient I apply the load for x amount of time, then let it go.
viewtopic.php?p=20818&hilit=abaqus#p20818
Re: Restart
Thank you Kevin for your reply.
In the past, I've done a study following your suggestion (loading for a x acount of time and let it go), and I works well. I could see the damping of the structural part.
But now the problem is different, I will do it whitout restart like this :
0 <time < t :
- loading on boundary 1 (Dirichlet conditions, position of the nodes)
- fixed at 0 on boundary 2
time >= t :
- fixed on boundary 1 (strain position at time = t)
- free on boundary 2
does this look ok?
In the past, I've done a study following your suggestion (loading for a x acount of time and let it go), and I works well. I could see the damping of the structural part.
But now the problem is different, I will do it whitout restart like this :
0 <time < t :
- loading on boundary 1 (Dirichlet conditions, position of the nodes)
- fixed at 0 on boundary 2
time >= t :
- fixed on boundary 1 (strain position at time = t)
- free on boundary 2
does this look ok?
Re: Restart
I was thinking of changing my Dirichlet conditions with the transient, but I don't see how to do it.
I want to block nodes for a period of time and release the blocks afterwards. In other words, I want to apply 1 boundary condition only for the first steps.
Boundary Condition 1
Target Boundaries(2) = 18 85
Name = "BoundaryCondition 1"
Displacement 1 = Variable "time"
Real MATC "if (tx<=0.8) 0.0;"
Displacement 2 = Variable "time"
Real MATC "if (tx<=0.8) 0.0;"
End
=> it doesn't work because there is no value for the displacement variables after t >0.8.
How can I do ?
Should I go into restart mode with new boundaries conditions ?
I want to block nodes for a period of time and release the blocks afterwards. In other words, I want to apply 1 boundary condition only for the first steps.
Boundary Condition 1
Target Boundaries(2) = 18 85
Name = "BoundaryCondition 1"
Displacement 1 = Variable "time"
Real MATC "if (tx<=0.8) 0.0;"
Displacement 2 = Variable "time"
Real MATC "if (tx<=0.8) 0.0;"
End
=> it doesn't work because there is no value for the displacement variables after t >0.8.
How can I do ?
Should I go into restart mode with new boundaries conditions ?
-
- Posts: 2355
- Joined: 25 Jan 2019, 01:28
- Antispam: Yes
Re: Restart
I would have to test if doing by restart allows you to change boundary conditions.
Otherwise there are conditional boundary conditions
Displacement 1 = Real 0.0
Displacement 1 Condition = Real $condx
When $condx > 0, the condition is enforced, when $condx < 0, not
So perhaps
Displacement 1 = Real 0.0
Displacement 1 Condition = Variable Time
Real MATC "if (tx<=0.8) 1.0; else -1.0;
"
Otherwise there are conditional boundary conditions
Displacement 1 = Real 0.0
Displacement 1 Condition = Real $condx
When $condx > 0, the condition is enforced, when $condx < 0, not
So perhaps
Displacement 1 = Real 0.0
Displacement 1 Condition = Variable Time
Real MATC "if (tx<=0.8) 1.0; else -1.0;
"
-
- Posts: 2355
- Joined: 25 Jan 2019, 01:28
- Antispam: Yes
Re: Restart
I redid the transient damping test with displacement BC instead of load force, and the results look reasonable. it vibrates after being let go.
Re: Restart
Thank you very much Kevin, I will test it tomorrow !