The study is part of the ”Structural conception and COllapse control performance
based DEsign of multistory structures under aCcidental actions (CODEC)” (2012-
2015) research programme, partially funded by the Executive Agency for Higher
Education, Research, Development and Innovation Funding (UEFISCDI), Romania,
(under grant PN II PCCA 55/2012), that aims to provide guidelines for a proper
design in preventing and mitigating progressive collapse. The activity within the
present dissertation work has been supported in the framework of the CODEC
project and represents namely the preliminary numerical simulation of the subassemblies.
The main objective of this work is to perform full 3D Nonlinear Static
Analysis for the loss of the central column of the sub-assembly in the case of only
steel structure and in the case of composite concrete-steel structure, using Finite
Element Analysis software, Abaqus. The document will present the modeling process
starting from simple 2D steel models to complex and sophisticated 3D steel-concrete
composite ones, considering composite action of the slab. Analysis were carried out
to evaluate the vertical displacement and plastic deformations and to study the
redistribution of forces, especially the development of catenary action (steel structure
only) in beams and membrane action (composite structure) in the slab. Parametrical
studies were developed in order to investigate the factors influencing the
development of catenary and membrane forces in the case of large displacements.
The contribution of the catenary and flexural action to the total capacity of the
structure was studied, concluding the potential catenary action of structural
members under extreme deformations, which can potentially increase the loadresisting
capacity of beams compared to flexural capacity alone. By the evaluation
