[solved] What are the units in FEM?

[baudri]

Hi,

first, I would like to say thanks for FreeCAD. I used it from time to time to model parts for 3D printing. Today, I made my first FEM and was quite successful. At least, I got a colorful output .
Now my question: I selected StressValues, but I cannot find any units. How can I figure out, what the units of StressValue (and the other selectable outputs) is?

Thanks in advance!

[heda]

Hi,

welcome to the forum.

am confused, at least on my box the units are always given per listed value, and they "adjust" themselves with prefix.

What preference settings do you have for units?

Attach a picture where units are not given?
It is not easy to guess what is on your screen...

Or is that you wonder what MPa or kPa is?
Pa = Pascal (SI unit for pressure) = N/m² : MPa = 1e6 Pa = N/mm², and k is kilo...

[Kunda1]

Moved to FEM subforum

[bernd]

How can I figure out, what the units of StressValue (and the other selectable outputs) is?

Which solver do you use? If it is CcxTools and your modell is made with mm than it is N/mm2 = MN/m2 = MPa Check the FEM Calculixcantilever example. Bending stress is between 450 and 500 N/mm2 AFAIR.

cheers bernd

BTW: make sure to read the huge red banner above the topic

[baudri]

Many thanks for the replies. And sorry for the late reply and the missing details.

I thought that I am using version 0.19, but I noticed that it is 0.18 on Windows 10 with which I took the screenshots below. I checked with 0.19 and my problem is still the same and is as follows:

I did the construction of the model in mm. Then I applied the CalculiXccx tools.

FreeCAD01.JPG (18.02 KiB) Viewed 1221 times

When I select StressValue from the Pipeline:

FreeCAD03.JPG (27.22 KiB) Viewed 1221 times

the result is properly displayed. However, I would expect a text with the property name (StressValue) and the unit somewhere near the legend. Or at least somewhere in the result display options.

FreeCAD02.JPG (158.26 KiB) Viewed 1221 times

I would like to know what the unit of StressValue (and other variables, when I select them) is. And I wonder where I can find the units or if I have to derive them from my length settings? I am a bit puzzled...

I also cannot find out what the units are in the cantilever example. Are they somewhere displayed?

Hope, the question is a bit clearer know?

[bernd]

N/mm2

[bernd]

https://github.com/FreeCAD/FreeCAD/blob ... py#L52-L75

[baudri]

Thanks!

[Kunda1]

Please mark thread solved by prepending [Solved] to the title of the 1st post.