Modeling of Reinforced Concrete Assemblies under Column-Removal Scenario

This paper presents a computational investigation of two reinforced concrete beam-column assemblies, each comprising three columns and two beams, subjected to monotonically increasing vertical displacement of the unsupported center column simulating a column removal scenario. One assembly was part of an intermediate moment frame and the other was part of a special moment frame. Two types of models were developed: (1) detailed models with highly refined solid and beam elements to represent the nonlinear material behavior of concrete and reinforcement, and (2) reduced-order models with significantly fewer beam and spring elements to represent the nonlinear behavior of structural components. Reduced models are desirable for analysis of complete three-dimensional (3D) structural systems. Modeling approaches for the detailed and reduced models are described, and the computational results are compared with experimental data from full-scale tests. Good agreement is observed, which demonstrates the capability of the detailed and reduced models to capture the primary response characteristics and failure modes, including the successive development of compressive arching action and catenary action in the beams and the fracture of reinforcing bars at the beam-column interface. (C) 2013 American Society of Civil Engineers.