What is the consideration when using built-up section?

When you create a built up section in the Section Wizard, it is imported into STAAD.Pro as a General section. Most of the design codes are designing this General section as an equivalent I section, so you need to bear this in mind when check the design results. Eurocode 3 is the only design code as of now, which can design General section not only as an I section, but also as some other standard section, like channel, angle, tube, etc. This can be selected by using the design parameter GST in the EN 1993-1-1:2005.

When you create a built up section in the Section Wizard, it is imported into STAAD.Pro as a General section. Most of the design codes are designing this General section as an equivalent I section, so you need to bear this in mind when check the design results. Eurocode 3 is the only design code as of now, which can design General section not only as an I section, but also as some other standard section, like channel, angle, tube, etc. This can be selected by using the design parameter GST in the EN 1993-1-1:2005.

Thank you for your response.

After registering query, I found that there are parameters such as STP, SNU. When designing according to AISC 360-10, are these parameters not required to be used?

SNU paramater is used for the  built-up members composed of two or more shapes interconnected by stitch bolts or welds.

You can use STP parameter for a built up as well as any other section.