Role of Composite Action in Collapse Resistance of Steel Frame Buildings

This paper investigates the role that flexural composite action between the concrete deck and underlying steel beams plays in the collapse resistance of steel structures. A 10-story, seismically designed steel building is used as a case study. The model employed in the simulation studies is a 3-D computational finite element model that accounts for the nonlinear, inelastic behavior of the most important structural components of the building. After validation, the simulation model is exercised to investigate system robustness when columns are forcibly removed, with specific emphasis on the role of the floor. The results show that slab-beam flexural composite action contributes significantly in the initial stages of collapse response, by reducing deformation levels and providing resistance against progressive collapse.