Abaqus error message: "REAL VALUE FOR PARAMETER RELATIVE MUST BE BETWEEN 2.22000E-16 AND 1.0000

[WillingToLearn]

Hello,

the title says it pretty much. I have an error message that I don't know how to address: REAL VALUE FOR PARAMETER RELATIVE MUST BE BETWEEN 2.22000E-16 AND 1.0000

I haven an explicit model that works fine with normal boundary conditions:

Fixed support at the bottom and displacement at the top.

But once I apply periodic boundary conditions and change the supports/loads accordingly, the model produces the above mentioned error:

The periodic boundary conditions are imposed, by using constraint equation and thereby coupling the DOFs of opposite nodes. In the implicit version this works just fine.

E: I want to mention that this error occurs during the data check.

Regards
Mike

 

[FEA way]

Are there any additional error or warning messages in output files ? Do these models differ only in terms of step type ?

 

[WillingToLearn]

Not even the step changed. Mentioning the implicit calculation probably only caused confusion, I just wanted to say, that the PBC did work in previous model.

What I have shown above (the working model) is already an explicit one. So I basically just changed the boundary conditions.

The .log file only states:
"Abaqus Error: Analysis Input File Processor exited with an error.
Abaqus/Analysis exited with errors
"

But for the above example I used a matlab p programm (that I bougth) to impose the PBC. When I use python, it now works (at least it looks like it). But looking at the model I can see no difference (the python vs. the matlab one)...very strange.

For now, the problem seems to have solved itself. If anyone knows what caused it: I am still curious

But the Periodic boundary conditions seem to drastically increase the calculation time (and the strange thing is: only ~15MB of RAM are used)...I stopped this one (combined shear + tensile load)

and I am currently running a model with coarser mesh size (to see if it works). But I already had to run on "double precision" otherwise it wouldn't work (changed mesh size from 0.1 to 10).

Hopefully the results will match those of the implicit calculation I did a while ago.