Run the exact same simulation twice but gain different results

Asked by Leonard on 2020-09-07

Hi,

When I carry out the triaxial compression simulation, I found that I run the exact same simulation twice but could gain different shear response, i.e., loading the same sample.yade.gz, and using the same script for deviatoric loading, but the stress-strain curve and volumetric response is not exactly same, see one example at [1] if you are interested.

I'd like to say that the results of the two are basicly agree very well, the only different just occurs at very large strains. I am strict about this because I wonder if there are anything wrong that I am not aware, or it is just some numerical random issues?

Thanks

Leonard

[1]https://we.tl/t-HlYiti9Q3V

Question information

Language:
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Status:
Solved
For:
Yade Edit question
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Solved by:
Jan Stránský
Solved:
2020-09-07
Last query:
2020-09-07
Last reply:
2020-09-07
Best Jan Stránský (honzik) said : #1

Hello,

please provide your code and how you run yade.
Basically:
- if you run Yade in parallel (using -j N option), it is expected behavior [1]
- if your computation/export depends on real time (e.g. realPeriod in PyRunner), you cannot expect exactly same results

cheers
Jan

[1] https://yade-dem.org/doc/formulation.html#result-indeterminism

Leonard (z2521899293) said : #2

Hello Jan,

Thanks for your reply.

>I use Bruno's triaxial script as the basic example code.
>I use -j N option, the documentation you shared exactly answers my question!

Cheers

Leonard

Leonard (z2521899293) said : #3

Thanks Jan Stránský, that solved my question.