Applying Wind loads to Diaphragms

[Anonymous]

Hello everyone, 

I am currently working on a 28 storey building and I have used the method @Romanich have developed to create diaphragms using Diaphragmer to create diaphragms in my model. And wind loads are applied to the master node of the diaphragm. In the calculation stage there are several Instability warnings. (I have attached a snap). So I have run the model without the Modal case( Otherwise there is a execution 3060 error). The problem is I'm getting very low lateral deformations for stories when compared with the results obtained from ETABS analysis.  Same wind loads have been applied to the both ROBOT and ETABS model. What could be the possible reasons for this?

Thanks in advance.

[Romanich]

Hi @Anonymous,

Instability type 1 cannot be ignored. Please check this webinar:

[Anonymous]

Thank you very much @Romanich