×
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

adaptive meshing errors

adaptive meshing errors

adaptive meshing errors

(OP)
hello,
I am doing a simulation of a hyperelastic material between two plates compressed by a rivet. I am using adaptive meshing for the hyperelastic material. But the solution aborts saying that one or more elements is highly distorted. Isnt adaptive meshing done to take care of high element distortion? then still why does the solution abort?
harry

RE: adaptive meshing errors

As far as I'm aware, only the /explicit code supports adaptive meshing, hence is it /standard or /explicit? You say you're using adaptive meshing, but how have you specified the parameters for this? Which adaptive mesh parameters have you input? Which elements are you using?  Are you using ABAQUS? Which version of ABAQUS are you using? What is the actual abort message? Is it related to the adaptive elements or some other elements in your model?

etc.
etc.

RE: adaptive meshing errors

(OP)
Hello,
Thanks for your reply.I am doing a 2-D axisymmetric analysis with Explicit now (version 6.4). It has a hyperelastic material between two plates compressed by a rivet. CAX4R elements. Initially, I tried the problem with standard but the hyperelastic material was getting deformed a lot and standard always aborted. Then after going through the manual I tried using  adaptive meshing to overcome the distortion with 3 sweeps per increment for the hyperelastic material.But that also aborted with excessive distortion. I tried increasing the frequency of sweeps also (no success).
Now I have just been trying in Explicit with CAX4R, distortion control, enhanced hourglass, Kinematic constraint formulation with surface to surface contact. My analysis does not even start. I have gone through the abaqus documentation on the error (listed below) and I understand where the error is coming from but I did not find in the manuals the way I can take care of the error. I checked all my properties and my model to make sure its right but no success.

Error:
***The ratio of deformation speed to wave speed exceeds 1.0000 in at least one element. This usually indicates an error with the model definition. Additional diagnostic information may be found in the message file.

***The maximum ratio of deformation speed to wave speed is Infinity in element 9 of instance SEALANT-1 at increment 2.

Thanks
harry

RE: adaptive meshing errors

Try to start off by performing a very simple linear static or modal analysis just to make sure everything is behaving in the model as you expect it to. Then you can try to diagnose the current error by adding more exotic loads. The error message gives no real indication as to the specific problem in the model. If you have contact, you may want to apply that in one step, just so the parts are touching. Then apply the full load in subsequent steps. You have in your favour the /explicit contact algorithm, which is much more forgiving - and in general more efficient - relative to its /standard counterpart.

Cheers,

-- drej --

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