Numerical simulation of conventional RC columns under concentric loading

Abstract

This paper aims to explore the correct prediction of stress-strain behavior and the determination of load ratio of conventional reinforced concrete (RC) columns subjected to concentric loading. Although there are numerous empirical confinement models are reported in the literature for the prediction of stress-strain response of the columns with conventional tie configuration under concentric loading, there is still an apparent need for the detailed analyses and more practical numerical models to provide further understanding of the stress-strain behavior. In this study, a comprehensive nonlinear finite element analysis (NLFEA) of square conventional RC columns under confining pressures has been performed improving the material parameters of Drucker-Prager criterion: cohesion and the internal friction. As in the previous companion paper of the author, these parameters were determined so that the Drucker-Prager failure cone approximates the whole compression meridian of the concrete up to the analytically predicted point of hydrostatic pressure obtained by making use of a realistic failure model. This crushing failure type model needs only the cylindrical compressive strength of concrete. As a result of this study, a new relation corresponding to the low levels of lateral pressure is also proposed for cohesion. A couple of experimental studies have also been presented here for the validation of the numerical method proposed in this work. The numerical analyses successfully reproduce the stress-strain behavior of 30 specimens tested by seven different researchers. (C) 2008 Elsevier Ltd. All rights reserved.