Applying moments directly to nodes

[TheLittleGuy456]

So I'm new to Abaqus and have a question. A colleague/classmate has provided me with and array of load data. I'm suppose to input those loads on a basic design, which is essentially a 3D circular cylinder. This is easy enough, since the concentrated forces can be easily applied to the nodes and defining boundary conditions is intuitive on this program.

But I am also given moment data that is suppose to be applied at both ends of the "cylinder". I cannot apply the moments directly to the nodes, since the nodes of these elements do not seem to have rotational DOFs. So, my question is: what is the best procedure to apply this moment data to the ends of the "cylinder"??

I have successfully applied moments to a reference point that is part of a "kinematic coupling constraint". However, I'm very uncomfortable using kinematic coupling because I do not fully understand what it does (the physics of it) and therefor I do not trust my results when using it. Can someone explain what this feature does?


I would greatly appreciate any responses/suggestions. I may not have provided enough info, but I'll readily give it if needed.


Thank you!

 

[IceBreakerSours]

Glad to see that you are suspicious.

Try a simple problem like a cantilever beam bending (2d or 3d). Instead of applying a concentrated force on a node, kinematically couple a few nodes on the free end to a reference point and apply the force at the ref point. See if the theoretical and numerical displacements match. Play around with this problem (in a scientific manner) by coupling less/more nodes and learn.

I suggest reading the Analysis User's Manual before trying this and reading it again after having played with the problem.

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[burningDiesel]

So what you want to do is apply a torque at the ends of the cylinder?
The approach of applying moment to a ref point and coupling those with the end nodes of the cylinder is the correct one.
In abaqus benchmark manual, check 2.1.1 torsion of a hollow cylinder