New Euler-Type Progressive Collapse Curves for Steel Moment-Resisting Frames: Analytical Method

In order to assess the robustness of a building structure to progressive collapse, the removal of a structural key component is utilized. For a steel moment-resisting frame under a column-removal scenario, the two most prominent collapse mechanisms are the yielding type (beam plastification) and the stability (column buckling) collapse mode. This paper presents an analytical method that can predict the progressive collapse mechanism of a 2D steel moment-resisting frame under any column-removal scenario and estimate the collapse load and location of the buckled column in case of loss of stability. The method uses only two linear elastic analyses and therefore avoids the computational cost that a complete progressive collapse analysis would require. The presented solution leads to the development of new Euler-type progressive collapse curves, which, similarly to the Euler curve for a single member under compression, refer to a steel frame and describe its response under any column removal. The new analytical method is applied through an extensive parametric study and the results are validated using advanced finite element simulation techniques, showing almost absolute consistency between the analytical method and the FEM results.