Numerical investigation on the shear behavior of prestressed concrete beams with small rectangular openings

The numerical investigation focused on the shear behavior of prestressed concrete (PC) beams with small rectangular openings, using the software ABAQUS. Three variables, including the prestressing force, the height of the opening and its length, were considered. The numerical results exhibited a good agreement with the previous experimental outcomes, and the parametric analysis was conducted to study the local internal force distribution of two chords during the loading process. The results indicate that for RC beams with openings, the shear proportion variation of the top chord is stable as the opening size changes, while it decreases almost linearly with the increase of prestressing force for PC beams with openings. The position of contraflexure point is found to be proportional to the root of the reinforcement ratio of the chord, and it moves towards the support with the increase of the prestressing force. Furthermore, the empirical equations to determine the shear proportions and the position of contraflexure point between chords are established.