C-CCommentary — Chapter C Design for stability
PDF page 401 · AISC 360-22
Chapter C has no major changes or additions in this edition of the Specification.
Design for stability is the combination of analysis to determine the required strengths of components and proportioning of components to have adequate available strengths. Various methods are available to provide for stability (Ziemian, 2010).
Chapter C addresses the stability design requirements for steel buildings and other structures. It is based upon the direct analysis method, which can be used in all cases. The effective length method and first-order analysis method are addressed in Appendix 7 as alternative methods of design for stability, and may be used when the limits in Appendix 7, Sections 7.2.1 and 7.3.1, respectively, are satisfied. A complete discussion of each of these methods, along with example problems, may be found in AISC Design Guide 28, Stability Design of Steel Buildings (Griffis and White, 2013). Other approaches are permitted provided the general requirements in Section C1 are satisfied. For example, Appendix 1 provides logical extensions to the direct analysis method, in which design provisions are provided for explicitly modeling member imperfections and inelasticity. First-order elastic structural analysis without stiffness reductions for inelasticity is not sufficient to assess stability because the analysis and the equations for component strengths are inextricably interdependent.