I am designing a steel frame and it has a member L3x3x3/8. The value of S and Z should be same for both minor and major axis. However STAAD Pro uses different values. Additionally, these values are not accurate with the AISC steel manual Table 1-7.
I am using STAAD.Pro CONNECT Edition - Version 22.02.00.26.
Those are values about the principle axis (not the geometric axis). https://communities.bentley.com/products/ram-staad/f/ram-staad-forum/113774/local-axes-of-a-single-angle
I am looking at AISC Table 1-7 where my Sz (principal axis) is 0.573 in3. And this value is different from the value provided from STAAD. Additionally, I would also like to ask how STAAD calculates "principal axis" for angles. Thank you. I have attached an image which shows value of Section modulus from AISC Table 1-7 for L3x3x3/8. Thank you.