Nonlinear Analysis For Behavior Of R.C. Horizontally Semicircular Curved Beams With Openings And Strengthened By CFRP Laminates

Abstract This research is consecrate to investigate the behavior and performance of reinforced concrete horizontally semi-circular curved beams with and without openings unstrengthened and strengthened externally by CFRP laminates or internally by steel reinforcement. Ten horizontally reinforced concrete semi-circular curved beams were tested in the experimental work one without opening and nine with opening. The variables considered in the test program are existence of opening in the beam strengthening of the beam at the opening region internally by steel reinforcement stirrupsand strengthening confinement by CFRP laminates externally for the region of openings. The beams were tested under the action of two point loads at top face of midspans with three supports at bottom face of the ends and midspan of the beams. The ANSYS software was use to analyze the finite element method FEM of both experimental specimens and the theoretical ones which contains the parametric study of different variables such as location of opening along the beam profile size and type of the opening and U-strengthening using CFRP Laminates. The results shows that the presence of opening has a great effect on the behavior and ultimate load capacity of semi-circular curved beams while the strengthening of these opening by internal steel reinforcement or external CFRP laminates will increase the ultimate load capacity and affect post-cracking behavior and mode of failure of these beams. The load midspan deflection and twisting angle curves are shown. The comparison between the experimental and the theoretical results are also listed. The results computed by FEM analysis and modeling gave a good agreement with experimental results.