I have a model which was created by a colleague of mine and i've now taken over. It was giving instability errors, and i could not get rid of them so i went through and deleted all the releases but i was still getting instabilities.
Is there any common reason that this might happen? If not would someone be able to have a look at the model and see if they can find any errors in it that might be causing this? I will upload it somewhere if so.
thanks!
Send us model to check
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Yes - i thought this might be the case. But when I removed all the releases I was still getting instability errors - is there some further underlying problem?
file with no releases:
https://www.yousendit.com/download/TEhYZm1kbThCMTd2WnRVag
Thanks for looking into it.
I was still getting instability errors - is there some further underlying problem?
merge nodes 796 1402
Model corrected http://wtrns.fr/oZNEZn3anfttNz - check diagrams etc.
I have removed some releases, new releases added : PP and Fixed Pinned no rx ; nodes merged.
Hello, thanks for your help so far. However when I open your fixed model and run it – I get a warning that says ‘Matrix is not positive definite’. This suggests that the model is unstable? (see image below)
<error1.PNG>
If I run the analysis with the DSC Algorithm turned on then I am still getting unstable nodes where they should be stable. (see image below)
<error2.PNG>
Is there any reason why this would be happening for me, but the model runs cleanly for you?
Thanks!
PaulGrimes2282 wrote:
Hello, thanks for your help so far. However when I open your fixed model and run it – I get a warning that says ‘Matrix is not positive definite’. This suggests that the model is unstable? (see image below)
Read the warning to the end ... check buckling.
Critical coeffs below 1 for nonlinear selfweight - check "upper branches of trees"