Finite element analysis of reinforced concrete deep beams with square web openings using damage plasticity model

This study investigates the behavior of RC deep beams with web openings based on the results of numerical simulations using the Abaqus/standard software. The numerical results of the validated specimens showed good agreement with the experimental ones. Then, the proposed concrete damage plasticity (CDP) model was used to examine the effect of various influential parameters, such as the shear span-to-height ratio (a/H), opening size, opening location, concrete compressive strength (fc'), main reinforcement ratio (rho s), and web reinforcement ratio (rho web). It was found that the presence of openings impairs the bearing capacity of RC deep beams, especially openings with sizes of 0.3 and 0.4 of the overall height of the beam. Moreover, openings located through the shear zone significantly reduce the ultimate load, especially on the loading path and near the bearing plates. This is due to the high concentration of shear cracks at the corners of the openings through the loading path line. The behavior of RC deep beams with web openings mainly depends on the openings' size and location. In addition, decreasing the shear span-to-height ratio increases the ultimate load. Meanwhile, increasing the concrete compressive strength (fc') increases the ultimate load. Similarly, increasing the main reinforcement ratio leads to a higher ultimate load due to adequate cracking control. The same finding can be revealed for the influence of the web reinforcement ratio on the bearing capacity of RC deep beams with web openings. Increasing the main reinforcement ratio from 0.45% to 0.57% and increasing the web reinforcement ratio from 0.29% to 0.33% can enhance the bearing capacity of RC deep beams by 11.36% and 3.26%, respectively. Finally, the numerical investigation reveals that the proposed simulated model can be used to effectively investigate the behavior of RC deep beams with openings overcoming their complexity.