Story-Based Stability of Multistory Steel Semibraced and Unbraced Frames with Semirigid Connections

A simplified method is proposed for evaluating the stability of multistory, steel, semibraced, and unbraced frames with semirigid connections. The decomposes a frame into individual stories evaluates lateral stiffness each story via story-based approach explicit, closed-form solutions. Lateral sway instability occurs when any diminishes to zero, which this can be considered weakest in frame. results are theoretically verified comparison finite-element analyses. use decomposition requires assuming buckled shape frame, shown provide satisfactory approximations critical loads engineering practice. Parametric studies conducted assess sensitivity corresponding buckling parameters. assumption asymmetric buckling, generally consistent mode semibraced frames, produces reliable method.