Fundamentals of structural analysis

XVII+734hlm.;26c

Fundamentals of structural analysis. 2nd ed.

xx, 758 hal.; ilus. ; 23 c

Development of Enhanced Seismic Compactness Requirements for Webs in Wide-Flange Steel Columns

Recent full-scale testing of steel wide-flange columns under axial compression and cyclic lateral drifts for special moment frame applications showed that deep, slender columns could experience significant flexural strength degradation due to plastic hinge formation with buckling modes and considerable axial shortening within the hinge. Test results showed that the interaction between web and flange local buckling played a significant role for the observed degradation, even when the cross-sectional elements met the highly ductile limiting width-to-thickness ratios specified in the current seismic design standard for steel frames. These observations were also confirmed by numerical simulations. Enhanced limiting width-to-thickness ratios for the web of a wide-flange column for both special and intermediate steel moment frames are proposed to limit the severity of strength degradation and axial shortening. © 2021 American Society of Civil Engineers.National Institute of Standards and Technology, NISTFunding for this research was provided by the Applied Technology Council under its Earthquake and Structural Engineering Research contract with the National Institute of Standards and Technology. Mr. J. O. Malley (Degenkolb Engineers) chaired the Project Advisory Committee. Mrs. A. Hortacsu (Applied Technology Council) served as the Project Manager. The authors would like to acknowledge the American Institute of Steel Construction for providing steel materials and The Herrick Corporation for providing fabrication of the test specimens

Application of Timoshenko Beam-Column Theory in Data Correction for Steel Beam-Column Testing

A recent cyclic test program evaluated the performance of steel wide-flange columns under axial loads and lateral drifts; the specimens had either fixed-fixed or fixed-rotating boundary conditions. For both cases, the flexibility of fully restrained moment connections at specimen ends, which varied in degrees based on several factors such as configurations of the bolted connection, end-plate thickness, and magnitude of the applied axial load, was observed to have significant impacts on elastic flexural stiffnesses of the measured responses. Therefore, the measured responses needed to be corrected, accounting for the effects of connection flexibility, before test parameters of interest can be investigated. A data-correction procedure that eliminates the effect of connection flexibility from the measured beam-column responses is developed. The procedure is built upon theoretical knowledge of elastic Timoshenko beam-column behavior. Once the effect of connection flexibility is removed, the corrected test responses become equivalent to the responses of beam-columns with ideal rigid end connections. (C) 2019 American Society of Civil Engineers.NEHRP Consultants Joint Venture Earthquake, Structural, and Engineering Research for the National Institute of Standards and Technology (NIST)Funding for this research was provided by the NEHRP Consultants Joint Venture Earthquake, Structural, and Engineering Research for the National Institute of Standards and Technology (NIST). American Institute of Steel Construction and Herrick Corporation donated the test specimens. Mr. J. O. Malley from Degenkolb Engineers chaired the Project Technical Committee, and Ms. A. Hortacsu from Applied Technology Council served as the project manager. The authors would like to acknowledge Dr. J. L. Harris III from NIST for reviewing this paper