Rigid support and beams

[ramihabchi]

When we can suppose a beam as rigid support for a slab?is there any deflection ratio for that?I have read on the internet that a thickness ratio of 3 between beam and slab guarantee rigid support behaviour.but in my case I want to know if there is a deflection ratio so I could for example check composite beams or hidden beams with high reinf ratio if they are enough stiff to be considered rigid

 

[BAretired]

Depends on your definition of rigid. A beam is never a completely rigid support because it deflects.

Where did you read that on the internet?

BA

 

[KootK]

We discussed very similar subject matter here recently.

 

[MSUK90]

in my case I want to know if there is a deflection ratio so I could for example check composite beams or hidden beams with high reinf ratio if they are enough stiff to be considered rigid

I will never consider any hidden beam to be stiff enough to carry load from slab..