Numerical Simulation of Nonlinear Behavior of Reinforced Concrete Beam-Slab Systems

Recent experimental tests on rectangular reinforced concrete (RC) beam-slab systems, subject to gravity loading, reveal that the mode of failure is generally a combined "beam-slab failure" (and rarely, a "slab-alone failure"). Theoretical studies have also established that the collapse load can be predicted accurately by yield line analysis, accounting for the formation of plastic hinges in the beams along with yield lines in the slab. However, techniques to predict the complete load-deflection plots of such tested beam -slab specimens have not yet been reported in the literature. This paper attempts to fill this gap by showing how a displacement -controlled numerical analysis using finite element analysis soft-ware such as Abaqus can capture the complete behavior, including the mode of failure. The concrete is modeled as a three-dimensional (3-D) solid element and the reinforcement is modeled as a one-dimensional (1-D) truss element, assuming perfect bond. It is seen that the numerically generated load-deflection plots are in good agreement with the experimental data. With the help of such numer-ical simulations, it is possible to carry out further studies on beam -slab systems with various configurations and possible combina-tions of beam/slab sizes and reinforcements, without needing to carry out laborious and expensive experiments in the laboratory.