Analysis About Hybrid Effects Of HFRP Bars And Research On Ductility Of Concrete Beams Reinforced With HFRP Bars

Hybrid Fiber Reinforced Plastics (HFRP) bar is a composite material,which is composed of two or more continuous reinforced fibers through the coordination of matching each other, resulting in synergistic effects and made of hybrid fiber reinforced polymer bar. It not only has the single fiber reinforced plastic bars of high strength to density ratio, good fatigue resistance, excellent corrosion resistance,magnetic and strong design ability. But also it has the"ductility"performance which the single fober reinforced plastic bar does not have .Also, the cost can be reduced.So, it is known as the dominant direction of fiber reinforcement in the 21st century. The HFRP bar is used in the concrete structures as a strengthening rebar because it has the similar"false surrender"stage of steel bars. The mechanical properties of hybrid fiber reinforced Plastics bar, is extraordinary different from that of the single FRP concrete. So they must be studied in depth.Based on the mechanical property test of HFRP bars and the experiment studies of HFRP reinforced concrete beams under vertical loads, the deflection prediction model of HFRP reinforced concrete beams is verified. And the ductility performance of the beam is characteristiced by sectional curvature coefficient and displacement coefficient. Major research contents and contributions are as follows:1. Research on mechanical property of HFRP barsThe mechanical property test method on elastic modulus, tensile strength and rate of elongation,etc.of different hybrid ratio of carbon/glass reinforced HFRP bar researched. The statistical tensile test results were analyzed , The stress - strain curves of different hybrid ratio HFRP bar were drawed. Under the law of mixture, the mechanical property index for structural design of HFRP bar were put forward,2. Finite element simulation of HFRP bar concrete beamThe nonlinear behavior for the whole Bending performance of the beams were analyzed by using ANSYS finite element software. It is introduced modeling method, selecting element, defining constitutive relationship of materials and solution method in the paper.3. Compared with the experimental results and the results of the ANSYS finite elementThe reliability of the finite element model is testified by compared with experiment results. The influencing factors to the deflection of HFRP bar concrete beam including hybrid ratio, the strength of concrete and the reinforcement ratio were studied in the paper. The calculation method of the prediction effective inertia moment with the HFRP bar concrete beam calculation is proved to be correct.4. Research on ductility of HFRP bar concrete beamThe ductility performance of the HFRP bar concrete beam is characteristiced by sectional curvature coefficient and displacement coefficient. The influencing factors to the ductility of HFRP bar concrete beam including carbon /glass hybrid ratio, the reinforcement ratio and the strength of concrete were qualitative researched by calculating.