Sap2000 Column size

[pxsm]

Hi, I am modelling a 3 story building and I am using 40x40cm columns. Some columns fail the stress/capacity check. If I decrease the size of those columns to 35x35cm, all the columns pass. This seems counter intuitive to me. Does someone know why this happens?. Thanks

 

[Agent666]

How does it compare to your hand checks? Do you show the same discrepancy?

How about providing detailed output from both cases so someone has a chance of actually helping you? You're asking a question but providing no information apart from some section sizes, no material, no spans, no load case under which this occurs, no explanation of design actions (are they even the same with the different sizes, I doubt it?), etc, etc, etc.

 

[JoshPlumSE]

Not enough information is given. Generally speaking the relevant information about columns is the following:

Area
Moment of inertia
unbraced length
yield stress


Compare those properties for the two columns. Despite one being smaller, it may have a larger area and / or moment of inertia.

 

[estructe]

Please check the design overwrites for each elemnt. Moreover you can disable seismic checks in order to have a clear look of the failure of the elements and then re-enable it.

Structural Analysis of 2D Structures software
Static, Dynamic,Linear and Non-Linear Analysis
of frames, trusses, beams etc.