ABAQUS I guess? Normally, I've found that a message about negative
eigenvalues indicates a problem with boundary conditions, generally a lack
of restraint, and your model has buckled. In this case, since you had a
sucessful linear elastic model, I would suggest that your material is much
"weaker" than the elastic case, and the model has buckled.
I guess it is possible to recover a fully elastic model from a
hyperelastic model? Maybe try matching the hyperelastic properties to the
previous elastic ones, and see if you get the same results. Then, if that
runs, progressively make the model weaker (or softer, if that is the
appropriate term). This assumes that the run time for the elastic case
wasn't too long.
Rod
> Hello, everyone!
> My 3-D hyper elastic model has been running for 20 days with only 2% total
> step finished. The same model has been completed successfully using liner
> elastic property. The only thing I changed was the material property from
> liner to hyper elastic. Warning message includes "457 negative egine
> values". Any suggestions?
> Thanks!
> David Wang
> BST 1654 East
> Phone: 412-648-8959
> Pager: 412-392-7221
>
__________________________________________________________________________
rod | "If morale is low it's because the employees have character defects.
| There is nothing you can do about that."
| from Dilbert's micromanagement tips for management.
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