Don White is a Professor at the School of Civil and Environmental Engineering (CEE).at the Georgia Institute of Technology, Atlanta, GA USA. He is a member of the AISC Specification Committee and has served as a major contributor to the AASHTO LRFD Bridge Design Specifications and the ANSI/AISC Specification for Structural Steel Buildings during the past 20 years. Dr. White received the 2009 T.R. Higgins lectureship award and a 2018 Lifetime Achievement Award from AISC, and the 2006 Shortridge Hardesty Award and 2010 Raymond C. Reese Award from ASCE for his research on design criteria for steel bridge and building construction. Dr. White is a co-author of the AISC Design Guide 28, Stability Design of Steel Buildings, and the AISC Design Guide 25, Frame Design Using Web-Tapered Members.
Advancements in the stability design of steel frames considering general nonprismatic members with general bracing conditions
D. W. White, R. Slein, & O. Toğay
Georgia Institute of Technology, Atlanta, GA, USA
This paper presents an innovative approach for design of planar steel frames composed of prismatic and/or nonprismatic members. The method uses a direct computational buckling analysis configured with column, beam and beam-column inelastic stiffness reduction factors derived from the ANSI/AISC 360-16 Specification provisions. The resulting procedure provides a rigorous evaluation of all member strength limit states accounting for moment and axial force variations along the member lengths, nonprismatic geometry effects, general out-of-plane bracing conditions, and beneficial end restraint from less critical adjacent unbraced lengths and/or from end boundary conditions. The approach uses a pre-buckling analysis based on the AISC Direct Analysis Method to estimate the in-plane internal forces, including second-order effects. The computational buckling solution addresses overall member stability, while other limit states are handled by direct cross-section strength checks given the calculated internal second-order analysis forces. The paper compares calculations from this approach to the results from recent experiments.