Investigating Effective Parameters in Shear Strength of Deep Beams without Shear Reinforcement

Investigating non-linear behavior of structures in order to evaluating vulnerability and determining performance level of existing structures is very important. Because of deep beams dimensions and also cost and time limitation and complexity of applying boundary conditions in lab, it is better to use software and non-linear analysis. In this paper the behavior of deep beams with lightweight and normal concrete and shear length to height ratio of 0.5, 1, 1.5 and 2 and also height of 30, 45, 60 and 90 centimeters is studied using Abaqus software. Results of non-linear analysis show that normalized shear strength decreases with increase in height in both groups of beams and this decrease can be seen in all shear length to height ratios. Comparing experimental results with truss methods available in codes shows that all methods are conservative in small height beams and safety margin reduces with increase in height. Results are non-conservative in CSA method in shear length to height ratio of 0.5 and in normal concrete, and with increase in shear length to height, predicted shear strength by CSA method is much more than strength obtained from analysis.