The Research On Mechanical Properties Of CFRP Plate Reinforcing Steel

This paper adopts the theoretical analysis and experimental research method of combining and making the explorative study on mechanical properties of CFRP (Carbon Fiber Reinforced pllymer laminate, shortened form CFRP) plate reinforcing steel beam. Total completeing seven root the mechanical properties and experimental study of CFRP plate reinforcing steel beam, compareing pasteing the different lengths of the CFRP plate reinforceing different injury steel beam with intact steel beam, analyzing the failure mode of the Specimens after reinforcement, the strength (yield load,reaching normal use limit state of load,limiting load), stiffness and ductility of improving the degree and rules, and the Specimens after reinforcement whether still according with flat section assumption is validated and completeing calculating and analyzing the utilization efficiency of CFRP plate. In addition, the possible failure modes and stress state of CFRP plate reinforcing steel beam on the basis of theoretical analysis, deriveing the strength calculation formula in elastic stage and the elastic-plastic stage, compareing the results of theoretical calculation and the experimental. Research shows:(1) CFRP plate reinforcing the injury steel beam can make its carrying capacity, bending stiffness, ductility to obtain the very good recovery, adopting the feasibility of strengthening modes is effectively validated. Usually the length of CFRP is longer, and its carrying capacity is raised, the effect of reinforcement is better; the depth of injury slot have greatly influencing on the strength, stiffness and ductility, Usually the deeper slot depth, the strength, stiffness and ductility weakened by the degree, And this slit width influence are small.(2) Injury steel beam adopt CFRP plate after reinforcement, it accords with flat section assumption in elastic stage, and also basicly accords with in plastic stage.(3) Analysing the strain difference value between the CFRP plate and Next flange steel informed:In calculation and analysis, specimen reaches the yield load and, if do not consider the relative slipping and fillet thickness between the CFRP plate and Next flange steel, approximate think the CFRP plate strain equal to the Next flange steel strain will bring certain error. Computing, should take the necessary measures to eliminate them.(4) Calculation and analysis found that the efficiency of the CFRP plate is only about 20% utilization in yield.(5) the results of deriveing the strength calculation formula are agreement with experimental results shows that the calculation formula has higher precision.