Identification of Limit Exceedance Points in a Reinforced Concrete Frame Under Pushdown Analysis Using OpenSeesPy

Progressive collapse is characterized by the propagation of local damage from an initial event, leading to the successive failure of structural elements and, eventually, the total or partial disproportionate collapse of the structure. Such damage can result from explosions, impacts, fires, earthquakes, construction errors, differential foundation settlements, exceptional snow loads, among other factors. Given the severity of these events, which cause material losses and, most importantly, pose risks to human life, research in this field has intensified. The analysis of progressive collapse is conducted through structural modeling using finite element software, with the pushdown method being widely employed. In this procedure, a column is removed from the structure, and a controlled displacement is applied at the removal point, while the corresponding force and displacement are recorded. In this study, the Python module OpenSeesPy will be used to assess the location of failure points where the steel exceeds a limit (initiation of plate formation) and the concrete exceeds a limit (crushing) in a reinforced concrete frame under pushdown analysis. The structural elements will be modeled as nonlinear beam-column elements using a layered approach (fiber section), which accounts for the distribution of stresses and strains across the cross-section. In this context, the aim of this paper is to evaluate a numerical model that will provide insight into the failure mechanism to which the structure is subjected after the pushdown analysis.