Structural collapse correlative analysis using phenomenological fiber hinge elements to simulate two‐directional column deteriorations

Abstract

SummaryThis paper presents three‐dimensional nonlinear dynamic analyses of a full‐scale four‐story steel building tested to collapse in 2007 at the E‐Defense shake‐table facility in Japan, using strong ground motion. Local buckling and consequent strength deterioration of all six columns at the first‐story level were observed as the main reason for the building collapse. Fiber hinge element that consists of fibers discretizing the column cross section is used model each end of the column. It has zero length but considers finite yield‐zone length for the fiber to simulate elastoplastic behavior and local buckling. Other parts of the building are modeled by standard column, beam, truss, and spring elements. Despite the unavoidable limitation of the parameters defining the fiber hinge element's properties that are empirically determined from the behavior of the cantilever column tested using an identical steel member, the analysis using the element appears to simulate well the column behavior because of the axial load and biaxial bending moment whose relative magnitudes differ considerably because of the locations. The analysis results indicate different deterioration patterns of the columns and effects of complex loading such as compression and tensile axial load applied alternately, additional high frequency axial load caused by vertical accelerations, and shifting of the principal directions of the bending moments cycle by cycle. Responses such as story drift, accelerations, base shear, and energy dissipation are also simulated well, and progress of local deterioration in the first‐story columns and global soft‐story mechanism is clarified by the analysis. Copyright © 2016 John Wiley & Sons, Ltd.