Extracting results data from Elmer

Post processing utility for Elmer
asandip
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Joined: 09 May 2019, 22:06
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Extracting results data from Elmer

Post by asandip »

Hello,

I am running an Elmer file which gives me the deflection in a square sheet of glass. The u_z values are available in Paraview. I am looking to extract these values to a text file. Are the results of the analysis stored in Elmer (is there a results file generated apart from the .vtu files)? If yes, which file? If no, is there a way to extract the results from the paraview without having to manually record them for the different time frames?

Thank you for any information you can provide.

- Anjali
mzenker
Posts: 1999
Joined: 07 Dec 2009, 11:49
Location: Germany

Re: Extracting results data from Elmer

Post by mzenker »

Hi,

you can use the savescalars solver (see models manual for more information) to save a variable to a separate file. In ParaView, you can use File->Save Data to save the variable e.g. to a csv file. It saves all data by default. If you (un)check the corresponding variables in the Properties tab of the Pipeline browser, you can select which variables (not) to save.

HTH,
Matthias
asandip
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Re: Extracting results data from Elmer

Post by asandip »

Hi Matthias,

I tried savesalars solver but the external file is blank (no results extracted). Also, I created a separate equation for save scalars and when I do that, the GUI does not let me select "Apply to Body 1". Please find the .sif attached and the solver section below.

Solver 2
Equation = SaveScalars
Operator 1 = min
Filename = uz_Elmer.dat
Variable 1 = Deflection
Procedure = "SaveData" "SaveScalars"
Exec Solver = After Timestep
End

Equation 1
Name = "Equation 1"
Active Solvers(1) = 1
End

Equation 2
Name = "Equation 2"
Active Solvers(1) = 2
End


The objective is to extract minimum value of deflection in the z direction for each of the time steps. Thank you for any help you can provide.

- Anjali
Attachments
case.sif
(2.47 KiB) Downloaded 219 times
mzenker
Posts: 1999
Joined: 07 Dec 2009, 11:49
Location: Germany

Re: Extracting results data from Elmer

Post by mzenker »

Hi,

the SaveScalars solver is active only in Equation 2. But Equation 2 is not applied to any object as far as I see. Try to remove Equation 2 and check the SaveScalars solver active in Equation 1 (I assume you use ElmerGUI).

HTH,
Matthias
asandip
Posts: 92
Joined: 09 May 2019, 22:06
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Re: Extracting results data from Elmer

Post by asandip »

Matthias,

I changed it to one equation -

Solver 2
Equation = SaveScalars
Operator 1 = min
Filename = uz_Elmer.dat
Variable 1 = Deflection
Procedure = "SaveData" "SaveScalars"
Exec Solver = After Timestep
End

Solver 1
Equation = Shell Equations
Procedure = "ShellSolver" "ShellSolver"
Displace mesh = True
Large Deflection = True
Exec Solver = Always
Stabilize = True
Bubbles = False
Lumped Mass Matrix = False
Optimize Bandwidth = True
Steady State Convergence Tolerance = 1.0e-9
Nonlinear System Convergence Tolerance = 1.0e-7
Nonlinear System Max Iterations = 100
Nonlinear System Newton After Iterations = 3
Nonlinear System Newton After Tolerance = 1.0e-3
Nonlinear System Relaxation Factor = 1
Linear System Solver = Iterative
Linear System Iterative Method = GCR
Linear System Max Iterations = 1000
Linear System Convergence Tolerance = 1.0e-8
BiCGstabl polynomial degree = 2
Linear System Preconditioning = ILU2
Linear System ILUT Tolerance = 1.0e-3
Linear System Abort Not Converged = False
Linear System Residual Output = 10
Linear System Precondition Recompute = 1
End

Solver 3
Equation = Result Output
Output Format = Vtu
Output File Name = case
Procedure = "ResultOutputSolve" "ResultOutputSolver"
Exec Solver = Always
End

Equation 1
Name = "Equation 1"
Active Solvers(3) = 2 1 3

But the .dat file is still blank. Thank you for any suggestions.

- Anjali
asandip
Posts: 92
Joined: 09 May 2019, 22:06
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Re: Extracting results data from Elmer

Post by asandip »

I was able to get some deflection values mapped onto the .dat file by adding save scalars to all the boundary conditions. The problem now is that, the numbers are not what I am looking for.

The goal is to extract the minimum value of the z component of the deflection (u Z) variable at all boundaries. Currently, the variable selected is "deflection". What should I change it to, to extract minimum u Z values (for each time step) to the .dat file?

Thank you for your help.
mzenker
Posts: 1999
Joined: 07 Dec 2009, 11:49
Location: Germany

Re: Extracting results data from Elmer

Post by mzenker »

Hi,

I was thinking that the problem might come from

Exec Solver = After Timestep

in a scanning simulation. But apparently this was not the case, as you were able to get some values written to your file.
Now which variable to use to get what you want I don't know, since I have never used the ShellSolver. If the information available in the Models manual doesn't help, someone with more knowledge on this solver has to take over...

Matthias
raback
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Re: Extracting results data from Elmer

Post by raback »

Change "deflection" to "deflection 3". -Peter
asandip
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Re: Extracting results data from Elmer

Post by asandip »

Thanks, Peter, I tried changing it to deflection 3, but here's the error I get -

ERROR:: SaveScalars: Requested variable does not exist: deflection 3

Please find the relevant files attached with this message. Thank you for any help you can provide.
Attachments
case.sif
(2.65 KiB) Downloaded 219 times
Elmer _Copy.7z
(305.17 KiB) Downloaded 188 times
kevinarden
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Joined: 25 Jan 2019, 01:28
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Re: Extracting results data from Elmer

Post by kevinarden »

The shell solver uses U as the deflection variable not Deflection, so it may be U 3

Kevin
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