Rigid body
Altair EmployeeHello Everyone
I am trying to tensile test analysis and for that I have made a dogbone shape in CATIA and then exported it to Optistruct. In the attached file, you can see that I have partioned it into several solids and then meshed it. Now I want to select the top part of the dogbone on one of the side (cubical shape) and make a rigid. So I created a node in the middle of the top part so that I can apply the loads there.Then I tried to create rigid using 'Geom>rbe3>independent node(by geom)>solids'. I selected the top solid, but it only creates node on one of the surface. I want all the nodes in that solid to be sected so that I can create the rigid.
I have attached the screenshot to make it clear and also attached the file
Would be grateful, if someone could help me out.
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Answers
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Hi,
The center node should be your dependent node and independent should be top nodes when creating RBE3
Why not use RBE2 instead?
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Hi Prakash
I understand the concept of indenpendent and dependent node. However, how do I select all the independent nodes. Doing it manually makes no sense. It takes too much time. How do I select all the nodes on the upper solid as independent nodes?
Thanks for your help
Sincerely
PS: Sorry I made a mistake in the above screenshot. I wanted to write 'dependent' in the centre. Accidentally wrote 'independent'. Thanks for pointing it out.
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Hi Prakash
Please let me know as soon as possible
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Hi,
Selec nodes by face and select any one node on top
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Hi Prakash
Thanks for the answer. I actually figured out the problem. I had forgotten to delete the 2D mesh and hence when I was trying to select by 'solids', it was just selecting the face.
I just deleted the 2D components and it worked.
Thanks for your help
However, I had another question regarding displacement boundary conditions in Optistruct. In the attached model, you can see that I have created a rigid on both the sides of the part. One side I want to keep completely fix and the other one I want displacement of 20mm. I am not sure how to apply the displacement value to the rigid node which I have created in my model.
Could you please have a look.
Sincerely
Jaivin
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Hi Prakash
Please reply.
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You can apply enforced displacement using SPCD.
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Hi Prakash
So I did the way you told showed me but I am getting an error which says 'Case Control data LOAD=3 is not referenced by any bulk data
relevant for used subcase type.'.Here is the file. Could you please tell me how to solve it?
Thanks in advance
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Hi Novak,
There is no need to refer any load collectors under LOAD when you have defined enforced displacement through SPC cards.
You can combine all the SPC load collectors to one SPCADD card and call this in SPC at load step level.
Thanks
Vikas
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