Numerical study of nonlinear behavior of deep concrete beams with rectangular opening in the web reinforced with FRP strip

The great depth of the deep beams allows the opening in the web. Openings in deep beams are intended for the passage of pipes and installation ducts. The presence of openings in the web cuts the members of the tie and strut in the equivalent truss and reduces the load-bearing capacity and ductility of the beam, which can even cause rupture. One solution to this problem is to use FRP reinforcing strips. In this research, the effect of FRP reinforcement sheets on the bearing capacity of deep concrete beams with rectangular opening has been investigated. For this purpose, reference laboratory samples were modeled and validated by finite element method with Abaqus software, then a number of parameters that may affect the response of the deep beam, such as the number, dimensions and distances of openings, were selected and kept constant. Other parameters, the response of the beam to its changes were examined. The results showed that the samples with BOX shaped reinforcement sheet had less bearing capacity than U-shaped reinforcing sheet. Also, samples with U-shaped FRP sheet have 38% more load capacity than sample without sheet and 13% more than BOX sheet. By comparing the reinforced specimens in terms of ductility and coefficient of behavior, it was found that the U-shaped reinforcing sheet has better performance.