[SOLVED]frequency analysis with multi materials

[aszodi95]

Hello,

I wanted to make a frequency analysis with freecad and calculix. First I made 5 cubes and then with "make compound" command I created one part.

1.PNG (57.87 KiB) Viewed 1753 times

After this in FEM workbench I defined the materials - shorter sections 15CrNi6, the longer sections AlZn4 (the aim was to take mass points on a beam).
Then I gave a force and a constrain to the beam.

2.PNG (49.81 KiB) Viewed 1753 times

Meshed it and tried to run calculix but it says the next error everytime. I tried it already with part unite (fusion) but the resolution was the same.

analysis_err.PNG (73.78 KiB) Viewed 1753 times

So, my question is, what do I have to chance in this process to get the results?
And thank you, in advance, for your help/answer!

[chrisb]

(moved to FEM forum)

[bernd]

- use a BooleanFragment instead of a Compound
- assign your material to a volume not to a area

[bernd]

find attaced an example ...

multi_mat_freq.FCStd

(543.44 KiB) Downloaded 68 times

multi_mat_freq.FCStd

(543.44 KiB) Downloaded 68 times

pic2.JPG (296.69 KiB) Viewed 1718 times

[bernd]

this may help too ... FEM_Shear_of_a_Composite_Block

[HarryvL]

Hello,

I wanted to make a frequency analysis with freecad and calculix. First I made 5 cubes and then with "make compound" command I created one part.

1.PNG

After this in FEM workbench I defined the materials - shorter sections 15CrNi6, the longer sections AlZn4 (the aim was to take mass points on a beam).
Then I gave a force and a constrain to the beam.

2.PNG

Meshed it and tried to run calculix but it says the next error everytime. I tried it already with part unite (fusion) but the resolution was the same.

analysis_err.PNG

So, my question is, what do I have to chance in this process to get the results?
And thank you, in advance, for your help/answer!

@aszodi95 from an engineering point of view, what behavior are you trying to model? For example, do you want to apply a harmonic load or shock load and see how the assembly vibrates?

[aszodi95]

Thank you very much, for your help!

[aszodi95]

#HarryvL

This is now just a practice, for me. In the future I have to analyse aeroelastic fluttering on an airplane's wing, and the simplified model will be a beam model. And the shorter sections with the higher density would be the mass points. So now I just tried to build a model, which is constructed from different materials.