Dear fmk: what's this problem?????

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fluozhen
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Joined: Thu May 07, 2009 7:33 pm
Location: nuaa

Dear fmk: what's this problem?????

Post by fluozhen »

"WARNING - ForceBeamColumn2d::update - failed to get compatible element forces & deformations for element: "(dW: << " << dW << ")\n";

I really don't know why is that? please help!!!!!!!



Many thanks.
fmk
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Post by fmk »

the force beam column needs to iterate at every step .. it does a newton iteration using the flexibility matrix, if that fails it does some modified newton iterations and tries cutting the step size.

your element is failing in these iterations which typically means that 1, though typically more, of sections are in the neg stiff region or have zero stiff and a sloution cannot be found.
fluozhen
Posts: 23
Joined: Thu May 07, 2009 7:33 pm
Location: nuaa

dear fmk&#65292; question again

Post by fluozhen »

[quote="fmk"]the force beam column needs to iterate at every step .. it does a newton iteration using the flexibility matrix, if that fails it does some modified newton iterations and tries cutting the step size.

your element is failing in these iterations which typically means that 1, though typically more, of sections are in the neg stiff region or have zero stiff and a sloution cannot be found.[/quote]

thank you for ur reply and I'm sorry to disturb you again. I did an eigenanalysis and found the stiff is 0, but I really can not find what's the problem, I really need your help ? Thank you so much.
fmk
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Post by fmk »

well if your stiff is 0, you have to change your input parameters.
fluozhen
Posts: 23
Joined: Thu May 07, 2009 7:33 pm
Location: nuaa

so many thanks

Post by fluozhen »

[quote="fmk"]well if your stiff is 0, you have to change your input parameters.[/quote]
thank you for your patience.
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