Numerical simulation of prediction of shear strength of reinforced concrete beam using total crack strain model

Abstract

Despite significant experimental, numerical and analytical research, the shear behaviour of reinforced concrete members remains one of the least understood mechanisms in reinforced concrete. Due to the complexity of shear behaviour, empirical or semi-empirical analysis approaches have typically been developed and these are widely employed in codes of practice. With the development of concrete construction industry, now it is common in construction of reinforced concrete moment resisting frames that some columns supported on beams as floating columns resulting a shorter shear span to depth ratio to beams. Furthermore, longer spans as well as shorter spans are in a single frame of multi bays to get the architectural appearance. However, the beam section designed for a longer span is continued even in the shorter span of the frame resulting shorter span to depth ratio in shorter bays. In the design stage of such elements, as a consequence that less attention paid in predicting the shear capacity than moment capacity, the brittle failures mode of beams in shear is observed before the ductile failure mode in moment. This actually violates the concept of ultimate limit state design. Therefore, the objective of the research study is to predict the shear strength of reinforced concrete beams using the total crack strain constitutive model and to validate the prediction with available experimental data in the literature. Simply supported beams are modelled with Midas FEA using Total crack strain model and their results are compared with the experimental results. Then the validated model is used to predict the shear strength of beams in monolithic construction. It was concluded that when predicting the shear failure of reinforced concrete members by total crack strain model, results were very sensitive to the defined shear stress strain relationship.