Strange behaviour of RBE3 elements

jan123

Hello,

I have a strange problem with RBR3 elements in a modal analysis. In the first picture you can see the original model and in the second one you can see the result after the calculation. The dependent node is marked red. It is loaded with a 1D mass element.

It seems like the dependent node changes during the calculation for no reason. I already checked for duplicate node IDs but couldnt't solve the problem. 

I did the same calculation with the same dependent node and the same independent nodes using RBE2 elements and it worked.

Can anyone help me and solve the problem?

Kind Regards,

Jan

Ben Buchanan

Just to make sure:

An RBE2 has one independent node and one or more dependent nodes.

An RBE3 has one dependent node and one or more independent nodes.

So with the RBE3 is the red node defined as the dependent node?

Hopefully this is it because otherwise you have some really strange stuff going on.