×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Coupling ref nodes to solids in Abaqus

Coupling ref nodes to solids in Abaqus

Coupling ref nodes to solids in Abaqus

(OP)
Hi,

I'm a little new to abaqus and having trouble with the following:

I've created a beam in C3D8I elements which I want to load in pure bending,
therefore, I have created 2 ref nodes at both ends. I have coupled the ref
nodes to the end surfaces of the beam using Coupling constraint. When I
apply a rotation to the ref nodes it does not transfer the rotation to the
beams surfaces, and the Riks analysis terminates. Now I'am aware this is wrong since Solids do not have
rotational DOF's, but I have not found another method to accomplisch what
I'm trying to do. Any suggestions?

RE: Coupling ref nodes to solids in Abaqus

The chances are very low, that two loads and the responses balance each other numerically exactly and create an equilibrium. So you should think about boundary conditions (recommended) or try options like Inertia Relief or Stabilization.

RE: Coupling ref nodes to solids in Abaqus

(OP)
I have used a Displacement/Rotation BC on both sides of the beam. Moreover, I found an earlier (Closed) thread which deals with the same kind of situation:

http://www.eng-tips.com/viewthread.cfm?qid=334975

I have used the same approach, but the rotation of the ref node still seems to not be coupled to the surface. As abaqus return the following error:

RE: Coupling ref nodes to solids in Abaqus

Try first to couple all DOF. Also check what happens with a regular static procedure, not Riks.

RE: Coupling ref nodes to solids in Abaqus

(OP)
Coupling DOFs U1, U2, U3, works, Rigidbody aswell. However, I'm still curious why coupling UR3 works in the other thread. Maybe it's the Riks analyses indeed, although I see no reason why. I will consider this one closed (solved-ish).

RE: Coupling ref nodes to solids in Abaqus

Nodes at solid elements have no rotational DOF, so you cannot couple them to something else.
And in the other thread it wasn't mentioned that it worked - it was just asked.

RE: Coupling ref nodes to solids in Abaqus

Why do you need to do Riks analysis for a pure bending deformation of a beam?

Also, the reference node you created is probably left unconstrained in the translation DOFs. Have you checked the warning/error messages in the log (.dat/.msg) files?

*********************************************************
Are you new to this forum? If so, please read these FAQs:

http://www.eng-tips.com/faqs.cfm?fid=376
http://www.eng-tips.com/faqs.cfm?fid=1083

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources