Non-linear finite-element modelling of reinforced concrete deep beams

The characteristic behaviour and failure mechanism of a deep beam is investigated using non-linear finite-element analysis in this study. An accurate stress-strain relation is incorporated to describe the stress-strain behaviour of the concrete under compression for uniaxial and also for biaxial stress states. Material non-linearity in the compressive stress field is considered for the concrete in the orthogonal directions and the effect of microcracking confinement and softening on the stress-strain relationship under biaxial stresses are included, employing the equivalent uniaxial strain concept. A computer code FEARCB (finite-element analysis of reinforced concrete beams) is developed to analyse deep beams until failure. The applicability of the proposed finite-element model is investigated by demonstrating the non-linear structural response and failure mechanism of different deep beams and comparing with the available experimental work. Good agreement is achieved between the developed finite-element model and the experimental test results.