I'm designing a steel shelter by portal frame with the span of 27 meter. Because the column is tapered section, I defined the member by "Tapered I".
If I use "CODE AISC UNIFIED 2005" for code checking, the design work by staadpro is ok. But If I use "CODE AISC UNIFIED 2010", there will be "WARNING: DESIGN OF SECTION FOR MEMBER # xx IS NOT SUPPORTED." and the warning members are the tapered columns.
I also tried to define a user table ISECTION for this, but the same thing happened. The tapered section can be disigned by AISC05 but not supported by AISC10.
I use "method LRFD". How can I make it if I want to use AISC10 for design?