special building vs intermediate building

[cris300]

hi everybody

I'm designing a building where the beams in the secundary direction fail by lb/ry>0.17 E/fy i cannot undertand why a secondary member required a section higher than the principal.

you can see the image i'm using etabs, and intermediate design for a building with 7 story

if i use LRFD93 to desing the members are good but using aisc 360-10 are bad, but is ilogical

please somebody that use aisc 360-10 with etabs talk about this results


thanks in advance

cris.

 

[12345abc6ttyui67]

The results to LRFD 93 and 360-10 appear almost identical. Why do you say one 'is good' and the other 'is bad'? Am I missing something...?

 

[cris300]

the beam are red in AISC 360-10 results because lb/ry>0.17 E/fy not by the ratio red mind failure in this software