×
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

Partition a volume mesh (bone)

Partition a volume mesh (bone)

Partition a volume mesh (bone)

(OP)
Hello all,
I want to simulate a three point bending test in Abaqus for a mouse bone. I use Mimics and 3-matic for modelling and volume mesh and then I import the file to abaqus for the FEA. My question is how can I create 2 partitions that divide the bone in two parts before importing it to Abaqus. The reason that I want to do that is because I want to constraint exactly the cross-section in the middle of the bone to move to the loading direction. I have tried it by selecting manually a ring of elements and then apply to them the boundary conditions but this will not give reliable results since I want to perform the 3pbt in different bones and then compare. I couldn't select the same ring of elements manually of course.

Any ideas??

Thank you

RE: Partition a volume mesh (bone)

(OP)
Please, could anyone recommend a possible solution?

RE: Partition a volume mesh (bone)

Partitioning is a geometry operation. It cannot be done on a mesh.
You have to bring the geometry to /CAE, partition that and then mesh it in /CAE.

RE: Partition a volume mesh (bone)

If you're applying a 3pt bending test then you wouldn't be applying the load or restraints to a cross section, but as the name suggests, to a point. Just select a node to apply the load to, or, better still, use contact with a rigid body which has the load applied to. It'll take longer to run with contact but then you're likely to apply the load over a region rather than a single point, which would give you very high stresses at that point.

RE: Partition a volume mesh (bone)

(OP)
First of all, thank you for your replies.
I attach 2 pictures of my setup. The boundary conditions I have already set are:
1) The supporting beams cannot move in any direction
2) The loading beam can move only in y direction for 1 mm. (It's a mouse bone with diameter ~2mm). So I apply a displacement and not a load in my set-up and I measure the reaction force to create the Force-displacement curve that I need for my experiment
3) There is a ring of element under the loading beam that is constrained to move only in the y-direction. These elements are chosen manually with a drag-box.

The concept of my general question is:
I'll test mice bones of different ages and I want to avoid limitations coming from boundary conditions that are not defined the same way. If I choose ring of elements in 24 different samples that I have, they will never be selected correctly in the middle of the bone, or exactly under the loading beam or the same number of elements or or or...


RE: Partition a volume mesh (bone)

I believe that #3 could be removed from the analysis if friction were included. You may need to provide global stabilization until contact occurs to remove any rigid body motions. This will avoid the arbitrary selection of noes to be constrained. This will allow the bone to settle in the test fixture.

I hope this helps.
Rob

Rob Stupplebeen
Rob's Engineering Blog
Rob's LinkedIn Profile

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