Composite beam analysis with plate and beam

[femana]

Hi all,

Composite beam sections come across in various structural engineering problems. For example in buildings floor slab and the beam, in bridges deck slab and the pre-stressed beam.

So when modeling this type of a structure we introduce an offset for the beam element to represent the actual location of the beam in the composite section.

After the analysis we observe that the bending moment in the beam is much less than what we expect.
But we observe an axial force in the beam element.

If we consider the stability of the beam element and the plate the stability is supported by the internal couple created by the axial force too.

So when doing the beam design we should consider this additional moment too.

So the actual design moment is Mz + (Axial Force)*Offset.(Assuming the beam local x is along the beam)