Too many attempts for Increment Error!!
Too many attempts for Increment Error!!
(OP)
hey all,
I am using the macro tool to record myself importing geometry and then setting up contact between parts automatically.
Then I change the 2d iges files I am importing using another cad package (catia) and am trying to get a contatc analysis to run with the specific geometry I have imported.
Anyway the problem I am having is that sometimes when I import the new gemetry and submit a job it works and other times I get the error 'too many attempts made for this increment error'
I am quite confused and hoping someone may know what this means
Thanks again
Conor
I am using the macro tool to record myself importing geometry and then setting up contact between parts automatically.
Then I change the 2d iges files I am importing using another cad package (catia) and am trying to get a contatc analysis to run with the specific geometry I have imported.
Anyway the problem I am having is that sometimes when I import the new gemetry and submit a job it works and other times I get the error 'too many attempts made for this increment error'
I am quite confused and hoping someone may know what this means
Thanks again
Conor
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RE: Too many attempts for Increment Error!!
corus
RE: Too many attempts for Increment Error!!
i found that when I had this problem, my (complex) surfaces weren't properly sticking together when using a tie.
I found that by upping the tolerance for the constraint, the number of unconstrained slave nodes dropped and the model appears to work as expected.
RE: Too many attempts for Increment Error!!
RE: Too many attempts for Increment Error!!
The way of solving problems is to check all infos in your .msg file :
first by running an analysis with *PREPRINT,CONTACT=YES in the model part of your .inp (between *HEADING and the first STEP) and adding *CONTACT PRINT in each step.
your analysis will give you very big .dat and .msg files with full info about all the contacts in the model.
Then many options :
- you read the contact details and detect "chattering" : a second order node opens, closes, opens, etc ... through the increments. Then use a more appropriate element type (linear element or 2nd order modified element - for example C3D10M instead of a C3D10)
- if you see that nearly all your contacts are realized and few are still opened or closed, you can allow code to make more attempts in step by using the *CONTROLS card (be careful this area is full of parameters, check it twice before re-running analysis) the default must be about 5 attempts you can define a bit more
- if you noticed a large occurence of the word "overclosure" followed by tiny values (i-e 1E-7) AND if your loading/boundary condition is not too large, you can switch the automatic tolerances by *CONTACT CONTROLS, AUTOMATIC TOLERANCES in the step part. ((reset to *CONTACT CONTROLS, RESET) in the next step .
To limit the problems with contact always try to use displacement approach instead of FOrce approach if possible.