Imported pressure from OpenFOAM

Hi everyone,

I am using PrepoMax to convert the pressure on the structure in openfoam to stress in calculix. When I import the OpenFOAM file, the software told me that the selected OpenFOAM folder does not contain results. I’d like to know how to do this step. The OpenFOAM folder and structure .STL file are shown in the github link: GitHub - NUGUY2022/OpenFOAM_Calculix: Convert Openfoam pressure to Calculix stress

Thank you so much.

Looking at your folder, maybe try renaming the folders 0.01 to 0.05 to folders without a dot “.” I am not sure, but it might be PrePoMax expects integer numbers as folders.

If it works, I must fix the PrePoMax code that searches for the results.

Thank you so much. You are right. PrePoMax can’t read files with “.” like “0.01” and other form like “001”. I modify the files as “1” and then it works.

Hi Matej,

I have one more question. When I run analyses after I finish all steps according to Youtube video of FEAnalyst, there is a warning “804 finite elements are missing a section assignment. Continue”. I don’t know what’s the meaning because I am a beginner of ProPoMax. Could you give me some suggestions?

Check the section definition. Maybe it wasn’t applied correctly.

Thanks for your notice. I didn’t define the section. Now I define the section and then it works.

Hi FEAnalyst,

I am sorry to disturb you again. I have one more question. Can PrePoMax output the stress of structure? I output the form of calculix.inp and find that there is no stress. Thank you in advance.

What kind of output do you mean ? Contour plots ? Those are of course available after running the analysis and opening the results (can be manually accessed from the .frd file). The .inp file is just an input file for the solver. After submitting it in PrePoMax (or directly in CalculiX), you obtain the results.

I just used the history output to get the stress value on the node and then output them by copying. Is it right?

You can use history output to obtain stress results but only for elements. Then, after opening the analysis results in PrePoMax, you will see the history output container in the tree and there you should find your tabular stress output.

Thank you so much. I have done it. :+1:

I output the stress by using history output and find that the stress is for node rather than element. So I want to output the element stress. How can I do ?

What makes you think that it’s for a node rather than an element ?

The number makes me think that it’s for a node. The total number of elements is 99 but there are 200 stress values. The number of stress match the number of node. I upload the .inp and stress files into the following link GitHub - NUGUY2022/OpenFOAM_Calculix: Convert Openfoam pressure to Calculix stress. Please check it.

Normally, there should be stress output from integration points of elements (that’s why there can be more entries than elements in the model). But your input file has no history output request so I wonder how you obtained those stresses.

I click the history output and then click the create. Then I choose the region and output S11 S22 S33 S12 S23 S13. I am strange too about that there is no writing data of history output in inp file.
Yes, you are right that stress output are from integration points of elements. So I need to merge this stress and element number to get the input file of initial stress.

To make sure that you define this correctly - is this how you do it?

History output stress

I am wrong. I didn’t create history output in FEA model module. I just created it in results module. Now I can output the stress on elements according to your video. Thank you so much.

1 Like