Composite beam

Hi,

I am trying to model a composite beam (steel beam + concrete slab).

For this purpose I modeled my composite beam as a steel beam and plate elements.

I applied then an offset distance 0.95 m to the steel beams. Now I see that the steel beam gets a very large axial force and the Mz moment at mid span is very small !!!

If I apply MEMEBER RELEASE (Fx) to the steel beams, the Mz moment would be correct, but what happents if I apply temperature load to the plate elements?

The axial force in the beams will be zero so this approach won't work properly.

I am really confused the way STAAD calculates section forces.

Do you have any clarification on this?

babmou

 

 

Composite Beam.std
Parents
  • Hi Sureshprsharma.

    Thanks for your follow up on this issue. Really appreciate it.

    As you see when I use the in-built Composite Beam option in STAAD, the maximum mid span moment will be Mz=5000 kNm and no axial force is induced either as you have verified in your excel sheet, but the problem is this model doesn’t work when temperature load is applied.

    My intention is to create a model comprising of beams and plate elements like “Composite Beam.std”.

    The question is how I can create a model to get same Mz and no axial force for pure bending due to gravity loads?

    I tried different ways such Master-Slave and skipping the OFFSET command, however I still get axial force.

    I don’t have any other software to verify if I get the same section forces.

    I know many users have the same difficulty in understanding the way OFFSET works.

    Have you any suggestions?

    I will be away for two days, but please keep on this discussion as it is very important for many other users too.

    Regards

    babmou

Reply
  • Hi Sureshprsharma.

    Thanks for your follow up on this issue. Really appreciate it.

    As you see when I use the in-built Composite Beam option in STAAD, the maximum mid span moment will be Mz=5000 kNm and no axial force is induced either as you have verified in your excel sheet, but the problem is this model doesn’t work when temperature load is applied.

    My intention is to create a model comprising of beams and plate elements like “Composite Beam.std”.

    The question is how I can create a model to get same Mz and no axial force for pure bending due to gravity loads?

    I tried different ways such Master-Slave and skipping the OFFSET command, however I still get axial force.

    I don’t have any other software to verify if I get the same section forces.

    I know many users have the same difficulty in understanding the way OFFSET works.

    Have you any suggestions?

    I will be away for two days, but please keep on this discussion as it is very important for many other users too.

    Regards

    babmou

Children
No Data