09-14-2010, 02:36 PM
Hello,
I’ve experienced similar problems in past models, especially for high rise buildings. When you check the reported node that supposedly has the instability, most of the times it doesn’t make sense. Anyway, what I’ve found is that still the model is reliable. If you check modal deformations and periods they are in the expected range. Also if you check seismic base shear it is also correct. So it’s probably some numerical bug that they haven’t been able to fix since past versions. Sometimes changing solution algorithm also helps.
Regards,
I’ve experienced similar problems in past models, especially for high rise buildings. When you check the reported node that supposedly has the instability, most of the times it doesn’t make sense. Anyway, what I’ve found is that still the model is reliable. If you check modal deformations and periods they are in the expected range. Also if you check seismic base shear it is also correct. So it’s probably some numerical bug that they haven’t been able to fix since past versions. Sometimes changing solution algorithm also helps.
Regards,
.