×
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

Time increment required is less than the minimum required

Time increment required is less than the minimum required

Time increment required is less than the minimum required

(OP)
Hello All,

I have a recurring error that is prohibiting any analysis on an punch indentation test (aximsymmetric).

I tried using an adaptive mesh and for some reason abaqus is removing it upon submitting it to the program. Can someone help me with this? I'm out of ideas (i've been poring through the message files...)

Any clues on BreastDimd?

Thanks in advance!

RE: Time increment required is less than the minimum required

(OP)
There is a particularly peculiar part of the analysis -- upon aborting, I look at the partial attempted solution and if I zoom very closely into the beveled corner of the indenter and the substrate immediately underneath it, I see the substrate actually going through the rigid body...

I believe this may be related but I'm not sure in what way...

Thanks in advance

RE: Time increment required is less than the minimum required

(OP)
Any good recommendations?

RE: Time increment required is less than the minimum required

(OP)
I think I have identified the problem to be a local instability due to too much deformation.

When I limit my displacement boundary condition (what I'm using as the defining act for my rigid body punch-indentation test), the model runs with no problem.  When I try a displacement of about 2% of the total height of the specimen, but when I try to get to 5% or 10%, I get "too many increment" and "the increment needed was smaller than the minimum allowed" errors that make the analysis abort.  I believe that there may be softening or rupture occurring near the edges of the indenter?

I was wondering how can I get these larger deformations to continue? Can I specify manually just a larger yield stress for this substrate [deformed] material? Should I attempt a Riks method static analysis?  If I make the material ultimately stronger, shouldn't these errors disappear?

RE: Time increment required is less than the minimum required

Do you try to change minimum increment size in job defining? Sometimes 1e-5 is to low. For steel properties sometimes 1e-7, 1e-8 is proper, especially with contacts.  

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