Interaction between Shear Failure and Flexural Failure of RC Beams without Stirrups Using a Numerical Approach

There are already many models for predicting the shear capacity of RC beams and one-way slabs that recognize the importance of flexure on the shear capacity. This paper takes this recognition one step further and shows that not only is shear affected by flexure, as already recognized, but also that flexure is affected by shear. It is not a question of the apparently separate issues of shear failure and flexure failure, but instead of the interaction between shear and flexure that gives the capacity of RC beams. With this understanding, it is shown that members that are subjected to transverse shear fail by flexure but at a lower moment because the transverse shear weakens the concrete in compression, i.e., the concrete compressive strength reduces as the transverse shear stresses increase. To illustrate this unique approach for simulating member failure, a free-body segmental model is developed to quantify the interaction between flexure and shear to determine the capacity of an RC beam with only tension reinforcement, which is then validated with good correlation with 206 published tests.