×
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

Crack propagation problem

Crack propagation problem

Crack propagation problem

(OP)
Hi
I am trying to model crack propagation using critical stress criterion. But Abaqus shows this error:
"**ERROR: Nodes adjacent to 1 current crack-tip nodes have debonded. The current crack-tip nodes cannot be debonded since the distances measured may be beyond the next crack tip nodes or the rest of the bonded surfaces have debonded. Critical stress criterion may not be applicable anymore. The nodes have been identified in node set ErrNodeCrackTipNodeDStep2Inc494."
I changed a lot of variables including the nodes position to increase the distance between nodes, but it doesn't work.
I will be very grateful if sombody help me.

RE: Crack propagation problem

That's because the crack is a discontinuty across the surface.  I think that SolidWorks does a better job in it.  Try modelling the crack as a seam which is subject to lateral and transverse loading.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

RE: Crack propagation problem

The stress criterion is evaluated ahead the crack-tip
....as long as there's some ligament left.

Are you sure the the surfaces (initially in contact) are long enough (i.e., they still contain bonded nodes) such that the position at which the critical stress criterion is evaluated to be before the last pair of bonded nodes ?

RE: Crack propagation problem

(OP)
Thank you all for your answers
 I think I could find the answer elsewhere. I decrease the total time of analysis. it can reduce the propagation of stress between nodes  and  the nodes debond before stress in next bond reaches the critical stress. BTW (for answering the question of Xref) I have enough nodes bonded before the end of process.
 But now other problem happens.
The stress in each node reaches the critical stress and then the contour of stress goes to the next bond and stress increase again but the previous bond is steel bonded ( it isn’t separated).
Can you tell me why the nodes remain bonded when the fracture criterion is satisfied?
Thank you

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