ASCE 41-17 Steel Column Modeling and Acceptance Criteria

The ASCE 41 Committee is currently completing the balloting of revised steel column modeling and acceptance criteria which will be included in the 2017 edition of the standard. The revised column criteria are a significant update to the current ASCE 41-13 provisions, and are based on research performed by Popov (1975), MacRae (1989), Brownlee (1994), Newell-Uang (2008), Uang-Ozkula (2015), Suzuki-Lignos (2015), Elkady-Lignos (2015) and limitations highlighted by Bech et al (2015) with the current criteria. The updated steel column modeling and acceptance criteria are based on a series of regression analyses performed on 220 different column hysteresis collected from the various researchers outlined above. The regression analyses were performed to fit the “a”, “b” and “c” parameters as defined by section 7.6 of the ASCE 41 standard. The completed equations and justification for the input parameters are presented along with the statistical measures taken from the regression. For seismically compact sections with low to moderately-high axial loads, the parameters and equations correspond with ductile, deformation-controlled behavior, rather than force-controlled behavior per ASCE 41-13. In general, the revised criteria result in less conservative predictions of column performance relative to ASCE 41-13. It is thus anticipated that the revised ASCE 41-17 provisions will result in less costly and intrusive retrofit solutions, and better characterizations of performance, than were developed under prior editions of the standard.