Depressions in slabs

[pevelor]

Hi

I have a slab with depressions, and I am wondering the correct way of modelling this.

What I have done is the following:

1. Define contour of the main slab.

2. Assign thickness to the main slab

3. Define a new contour inside the first slab for the depression.

4. Assign thickness for the depression

I am afraid the stiffness might be incorrect if the main slab does not have openings where I assign new panels (depressions). In other words, will the stiffness be correct?

Regards

Peder

[Artur.Kosakowski]

Yes, it will.

[pevelor]

Thats what I figured. So in other words, when I create a new panel inside another panel it will create an opening in the main panel....

The reason I got concerned I because of the values obtained in rc design

Could you explain why I get higher values where I have depressions? (All slabs have identical material)

[Artur.Kosakowski · Accepted solution]

Thats what I figured. So in other words, when I create a new panel inside another panel it will create an opening in the main panel....

It will create a panel with elements of different thickness. If you create a contour then it will create an opening instead.

I'm sorry but having only the picture  I'm not able to figure out what you actually modeled. Please check values of displacements and internal forces first to understand the behavior of the structure (make sure that the model behaves as you wanted it to do). The reinforcement is just the secondary result so usually this is not the area you should start your investigation with.

BTW: I may be wrong but assuming that you have continues transfer of bending along the slab the same value should cause larger reinforcement in the part with the smaller thickness.