A bit different in sap2000 and ETAB is it a problem

[samnang]

could anyone explain me

when i start to model a beam in sap2000 and ETAB i find that
-in SAP2000 the beam center line is along the mid section of the beam
-but,in ETAB the beam center line is at top fiber


does it have any bad effect to the result of analysis or design or not?
Can we change it?

please see picture i attached

 

[ishvaaag]

See thread

http://www.eng-tips.com/viewthread.cfm?qid=310803

the respective programs will calculate solicitations as your page portraits. The etabs setup places the beam where it is expected to be for beam plus floor design, and if some plates are added in the normal setup will be coplanar with the upper flange, so results will be adequate to composite analysis. If no slab is drawn, there will be as well some difference between the calculations along your top and bottom schemes, given the different geometries of the centerlines of beams.

When no slab is placed, the difference should be small, and more or less both schemes should be adequate for steel-only structures.

In any case it is better the models follow the actual position of the conceptual components. You can use the tools within the programs to accomplish such intent.