Minor axis flexure and combined loading response of I -shaped steel members

• Main Author: Aktas, Muharrem
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-2004
• Subjects: Civil engineering
• ISBN: 9780496915682; 0496915681

The present dissertation elucidates the problem of determining if a given I-shaped cross-section is properly proportioned to accommodate sufficient plastic hinge rotation capacity to facilitate the redistribution of moments in a structural system as needed to accommodate the formation of a collapse mechanism. It might be tempting to believe that application of the limiting flange plate slenderness value for the case of major axis flexure are applicable in this case; since the pervasive belief is that this approach ought to be conservative. However, the present research study indicates that this is not the case and thus more sophisticated analysis techniques are required to better understand this case. Most current design specifications employed throughout the world prescribe the use of so-called interaction equations for the design of beam-columns. Most often these interaction equations are optimized for use with the members possessing I-shaped cross-sections that are bent about the major principal centroidal axis while simultaneously being subjected to compressive thrust. The current study then also focuses on the case wherein an I-shaped member is loaded in compression and simultaneously bent about the minor principal centroidal axis. It is shown that the current AISC interaction equations can be improved on in terms of their ability to predict failure in these types of members. Alterations to the existing AISC interaction equations are suggested for improving on strength predictions relative to this case. Through these two research focuses, the present dissertation adds significantly to the state of knowledge surrounding the response of steel members possessing I-shaped cross-sections that are subjected to minor axis flexural effects; effects that are important to the robust and redundant design of structures in a system-wide sense.