Modeling for opening

[alphaxy]

Hi fellows

I would like to know what would be the difference If I will model an opening in etabs rather than just leaving it without any slab or deck?

Is there a significant effect for this matter?

Thanks
AlphaXY

 

[slickdeals]

No difference, one is easier 'cos you don't have to draw the trim the slab around opening. It takes care of it by auto-meshing.

 

[alphaxy]

Thanks Slickdeals. I have warnings in my model and trying to locate it. I'm wondering if this has something to do with it.

However, upon my first run I obtained an ill conditioned result, but I resolved it already. I overlooked the mesh in transfer slab and one of the columns.

* * * W A R N I N G * * *

THE STRUCTURE IS UNSTABLE OR ILL-CONDITIONED !!

CHECK THE STRUCTURE CAREFULLY FOR:

- INADEQUATE SUPPORT CONDITIONS, OR

- ONE OR MORE INTERNAL MECHANISMS, OR

- ZERO OR NEGATIVE STIFFNESS PROPERTIES, OR

- EXTREMELY LARGE STIFFNESS PROPERTIES, OR

- BUCKLING UNDER P-DELTA LOADS (IF ANY), OR

- AN EIGEN SHIFT (IF ANY) ONTO A NATURAL FREQUENCY

Do you have any idea, if it is not a mesh problem, what should I check? In case, this may happen again. I noticed, When I run the animation of the model, the slab and the wall seems not restrained though I already defined the auto restrained and also meshed it. Is it important to align the mesh in the wall to mesh in slab?

Thanks
AlphaXY

 

[Murali27]

Hi AlphaXY

It appears that there is an issue with structure. Sure you could review point displacements or modal displacements to locate the issue exactly. It may be due to meshing especially in transfer column condition. Please also ensure the right definition of slab type (membrane or shell) in the model.

Hope this helps