How to solve the error of ERROR # 941 ?
Altair EmployeeI have met this error
*** ERROR # 941 ***
NON-CONVERGENT NONLINEAR ITERATIONS FOR SUBCASE 2
Suggestions:
* Friction or STICK can cause more difficult nonlinear convergence - if feasible
try frictionless gap/contact.
Or try stabilized version of expert system: PARAM,EXPERTNL,CNTSTB.
* This problem has gap elements with friction or stick condition. For more
intuitive results and often better convergence, set GAPOFFS on GAPPRM card
to AUTO. (This may violate rigid body balance, especially for unsupported
structures.)
And I have read the reference article at here by @Prakash Pagadala 's reply
Can you increase the NINC and MAXITER values in NLPARM card and check if your run converges or not?
Also, use PARAM,EXPERTNL,YES and CONTPRM,STIFF,SOFT
and I have changed like that but it still can't convergence
1. NINC → 30
2. DT → 0.01
3.MAXITER → 45
and at here I also set contact of SOFT, PARAM → EXPERTNL → YES and open CNTSTB (in load collector)
My model has pretension groups of 8, contact groups of 80 and I have plused gravity on it.
How can I change to solve this error in effect?
This is my out file
--------------------------------------------------------------------------------------------------
I also have a question can I first to run a pretension by a case.
Maybe we will have a h3d file of it.
So we can use this h3d result to add in other case and it will run without the solved time.
Because I know we can set 2 loadcase in a file but if today we have many project to solve.
And at the loadcase 1 they are the same, they just different at loadcase 2.
We can bypass the time of loadcase 1.
This idea just like the superelement and How can I do this.
Answers
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@Prakash Pagadala Because I forget to set a contact of one bolt.
I finally applied a pretension on it and it is analyzing now.
I can sent you the before h3d by the security link.
Really thanks.
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OK thanks, I can see for load case 1 99% is applied and fails at 100% load and load case 2 fails instantly.
so, just want to see if it something to do with modeling..
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@Prakash Pagadala Thanks to your apply
I now find it can convergence at load case 1.
And the loadcase 2 I have find the contact missed will caused the part flying away. (I plus it contact now)
This is the gif
<?xml version="1.0" encoding="UTF-8"?>
I will wait for it analysis result.
If it still has problem, I will ask for you at here.
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@Prakash Pagadala I have sent the file for you
And do you know my second problem? about this ↓
I also have a question can I first to run a pretension by a case.
Maybe we will have a h3d file of it.
So we can use this h3d result to add in other case and it will run without the solved time.
Because I know we can set 2 loadcase in a file but if today we have many project to solve.
And at the loadcase 1 they are the same, they just different at loadcase 2.
We can bypass the time of loadcase 1.
This idea just like the superelement and How can I do this.
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From h3d you can only export the deformed shape. You have to go through the modeling phase again.
I am thinking about RESTARTW and RESTARTR where a restart file will be written which has model information and analysis information.
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@Prakash Pagadala Thanks to your apply!
So if I want to do this I just can modify the loadstep 2.
And restart the analysis again. I can't saved the time of solving the loadstep 1.
If the first case need to run 4 hours of loadstep 1 and 2 hours of loadstep 2.
At the second case I need to run 4 hours of loadstep 1 again and plus new time of loadstep 2.
If the second case's load step 2 is 4 hours, I need 8 hours to solve it.
Does I describe it right?
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I am not sure how this will help.
I am going to check with experts as well on how to have such a simulation setup.
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@Prakash Pagadala Thanks to your apply.
I want to ask questions about contact and solver
Q1 : I want to ask about why someone will set a pair of contact and just change the master and slave
Q2 : If today I have 2 case to run but I don't want they run together. I want to run first case when it runs completely then the second case will start running automatically.
And I don't need to set the input file and press the run. How do I set that?
Really thanks.
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Altair Forum User said:
Q1 : I want to ask about why someone will set a pair of contact and just change the master and slave
Because contact happens between a pair or self
Altair Forum User said:Q2 : If today I have 2 case to run but I don't want they run together. I want to run first case when it runs completely then the second case will start running automatically.
And I don't need to set the input file and press the run. How do I set that?
This needs to be automated.
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Are both in different filew or same files?
The other question ypu asked about continuing loadcases, I am checking with experts
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@Prakash Pagadala Thanks to your apply.
About the Q2's situation, they will be two different fem.file
And I want to solve them. When first completed, it will start automatically in second fem.file
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