Beamless floor systems should be analyzed with a semi-rigid diaphragm.
The Complete Message:
Beamless slab systems should be analyzed with semi-rigid diaphragm acceptance.
In the article 126.96.36.199 of TBDY 2018, in buildings where there are A2 and A3 type irregularities according to 188.8.131.52 and / or floors are not intended to operate as rigid diaphragms and in systems with floors without reinforced concrete beams, floors will be modeled with two-dimensional finite elements .
In TBDY 2018 article 7.11.3 , in-plane axial and shear stresses in the floors of buildings with and without beams will be calculated with the acceptance of elastic diaphragm, the condition is also found.
Therefore, slab rigidities should be included in the analysis model.
Using the Analysis Settings / TBDY 2018 Analysis Settings Wizard , select the appropriate structural system, slab type and then select the semi-rigid diaphragm option.