SAP 2000 Cold formed steel design( difference of ratio between members)

[Islem]

Hello everyone,

please find attached the issue that i met during my design of a 15 m portal in cold formed steel using deep C 200x2,5mm sections for beams and columns

anyone can tell me why i have this difference in ratio between the two sides of portal.

thanks

Islem

 

[Islem]

hello everyone;

i am designing a shelter which has dimensions of 6m of width and 25m of length and 6m of height the my section for beams and columns is C200x40x11 (back to back)(2,5 thickness) ,during my vérification in accordance with AISI LRFD i found out that some columns have verified and some have not ,for beams none item has checked (O/S error) .
Please i wonder if there is any solution i can use , note that i have inserted the unbraced length ratio for all members..
thanks and best regards
islem.

 

[klaus.]

Are you a structural engineer ?

 

[Islem]

yeah i am but i am new in cold formed steel why ?

 

[jayrod12]

Those sections would be no where near adequate based on gut feel alone.

Are those envelope results you've posted, or just a single load case?

 

[Islem]

@jayrod12 yeah they are the enveloppe beams and column results .
about sections i know that are not adequate but when i desiegned a frame portal which has 12m of width all the members have been verified.
thank you very much for your help jayrod.


islem

 

[jayrod12]

If it's an envelope run, then I would expect them to have the same max code check values assuming the loading is uniform.

If the loading is uniform then I would look at each members design parameter, I.e. unbraced lengths.

 

[Islem]

Dear jayrod;

I checked another time and increased the section to C250x65x20 2,5 thickness the ratio has reduced a lot.

thanks for your help

regards

islem