AleksaBgd94
Structural
- May 30, 2018
- 52
Hi everyone,
I am modeling a 3D steel building with composite slabs. I have a few questions about modeling this composite slab as a diaphragm.
I used shell-thick elements, and assigned concrete as a material, bending and membrane thickness equal to 140mm.
Should I change any stiffness modifiers parameters?
Should I assign constraints - diaphragms to joints at each floor? If these diaphragm constraints are assigned to joints at each floor, does that mean that the slab will automatically act as a rigid diaphragm??? I ask this because there are very big differences in periods of construction when I assign contraints and when I don't.
And should any axial forces occur in the beams due to horizontal loads (wind and earthquake).
Is there something more I should do to connecet slabs with frames (beams). Does Automatic Area Mesh affect this?
I've already run a few models, and noticed that changing m11 stiffness modifiers affects periods of construction, and that's what I can't explain. Aren't f11,f12 and f22 those which are the most important regarding the behaviour of composite slab as a flexible/rigid diaphragm.
I appreciate your help.
I am modeling a 3D steel building with composite slabs. I have a few questions about modeling this composite slab as a diaphragm.
I used shell-thick elements, and assigned concrete as a material, bending and membrane thickness equal to 140mm.
Should I change any stiffness modifiers parameters?
Should I assign constraints - diaphragms to joints at each floor? If these diaphragm constraints are assigned to joints at each floor, does that mean that the slab will automatically act as a rigid diaphragm??? I ask this because there are very big differences in periods of construction when I assign contraints and when I don't.
And should any axial forces occur in the beams due to horizontal loads (wind and earthquake).
Is there something more I should do to connecet slabs with frames (beams). Does Automatic Area Mesh affect this?
I've already run a few models, and noticed that changing m11 stiffness modifiers affects periods of construction, and that's what I can't explain. Aren't f11,f12 and f22 those which are the most important regarding the behaviour of composite slab as a flexible/rigid diaphragm.
I appreciate your help.