Effect of the actual behaviour of structural joints on the steel frame response in case of column loss scenario

Abstract

The structural robustness is a relatively recent topic in the civil engineering world. Even though there are several researches and guidelines based on this subject, there are still many unknowns regarding the response of the structures in the case of exceptional event. Based on this context, the main purpose of this master thesis is to investigate the behavior of the beam-to-column connections on steel frames, in the event of the column loss. In more details, the study focuses on the influence of the partial-strength joints on the robustness of the structure, by their contribution to the arching effect and to the formation of the plastic mechanism. The first part of the thesis consists of the comparison between two analytical models, the objective of which is to determine the plastic load coming from the beam arch and from the formation the plastic mechanism. The two models were subjected to several parametric studies, in order to evaluate the results. It was confirmed through numerical analysis that the new approach brought an improvement to the accuracy of the results. The second part consists of parametric studies as well, based on numerical analysis, which emphasize the influence of the beam-to-column connection and of its components on the structural robustness. The simulations were performed in the finite element modelling program FinelG. Moreover, it was confirmed through numerical investigations, that the computation of total the plastic load can be simplified, depending on the similarity between the storeys of the structure.