Experimental Study On Mechanical Behavior Of Steelgirder Strengthened By Fiber Reinforced Polymer

For a long time,due to improper design and construction,disaster load and environmental effect,operating conditions and other reasons,some steel structures will have some diseases,which need to be repaired,reinforced and strengthened.Therefore,how to prevent the damage of steel structure and how to strengthen and repair the damaged steel structure has been the focus of research in the field of civil engineering.Fiber reinforced composites are widely used in the field of reinforcement because of their superior properties.In this paper,the effect of prestressing the fiber reinforced composite with steel beam arch back on the flexural mechanical properties of the reinforced structure is studied through experiments.The main work and conclusions are as follows:(1)after consulting relevant literatures at home and abroad and summarizing previous theoretical and experimental researches,the purpose and means of this study are proposed after analysis.(2)the flexural test of 4 beams(including 1 unprestressed reinforced beam and 3 prestressed reinforced beam)was carried out to study the influence of the method of prestressing CFRP on the flexural performance of the reinforced beam.The results show that the prestressing method can improve the bearing capacity of steel girder.The yield load of the prestressed steel beams B1,B2 and B3 with 100 kN,130kN and 160 kN anti-arch force is increased by 2.84%,3.64%,4.46%,1.40%,1.58% and 1.76%,respectively,compared with that of the non-prestressed steel beams A1.Since there is no pure steel beam in this test,on the premise that there is little difference between the theoretical calculation value and the test value,the calculated value is used to replace the test value of the pure steel beam,it can be obtained that the yield load of the non-prestressed strengthened beam A1 relative to the pure steel beam increases by 6.63%,and the yield load of the prestressed strengthened beams B1,B2 and B3 relative to the pure steel beam increases by 9.66%,10.50% and 11.14%.(3)according to the characteristics of steel girder strengthened with carbon fiber plate,the finite element analysis model was established by ABAQUS.Correctly in the finite element model on the basis of simulation test model,USES finite element analysis model to analyze the carbon fiber plate thickness,width,length and thickness of the rubber on the properties of reinforcing steel beams flexural impact,as to provide theoretical basis for the carbon fiber plate reinforcing steel rusty design,so as to further perfect the existing steel structure reinforcement design theory.