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.